diff --git a/src/js/game/base_item.js b/src/js/game/base_item.js
index 061681c0..61dc3f34 100644
--- a/src/js/game/base_item.js
+++ b/src/js/game/base_item.js
@@ -1,12 +1,8 @@
 import { DrawParameters } from "../core/draw_parameters";
 import { BasicSerializableObject } from "../savegame/serialization";
 
-/** @enum {string} */
-export const enumItemType = {
-    shape: "shape",
-    color: "color",
-    boolean: "boolean",
-};
+/** @type {ItemType[]} **/
+export const itemTypes = ["shape", "color", "boolean"];
 
 /**
  * Class for items on belts etc. Not an entity for performance reasons
@@ -25,10 +21,10 @@ export class BaseItem extends BasicSerializableObject {
         return {};
     }
 
-    /** @returns {enumItemType} */
+    /** @returns {ItemType} **/
     getItemType() {
         abstract;
-        return "";
+        return "shape";
     }
 
     /**
diff --git a/src/js/game/belt_path.js b/src/js/game/belt_path.js
index fc062bcc..9e665487 100644
--- a/src/js/game/belt_path.js
+++ b/src/js/game/belt_path.js
@@ -8,7 +8,7 @@ import { BasicSerializableObject, types } from "../savegame/serialization";
 import { BaseItem } from "./base_item";
 import { Entity } from "./entity";
 import { typeItemSingleton } from "./item_resolver";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 
 const logger = createLogger("belt_path");
 
@@ -203,7 +203,7 @@ export class BeltPath extends BasicSerializableObject {
         const targetEntity = this.root.map.getLayerContentXY(
             ejectSlotTargetWsTile.x,
             ejectSlotTargetWsTile.y,
-            enumLayer.regular
+            "regular"
         );
 
         if (targetEntity) {
diff --git a/src/js/game/blueprint.js b/src/js/game/blueprint.js
index ecffdc31..dc30554d 100644
--- a/src/js/game/blueprint.js
+++ b/src/js/game/blueprint.js
@@ -3,7 +3,7 @@ import { Loader } from "../core/loader";
 import { createLogger } from "../core/logging";
 import { Vector } from "../core/vector";
 import { Entity } from "./entity";
-import { GameRoot, enumLayer } from "./root";
+import { GameRoot } from "./root";
 import { findNiceIntegerValue } from "../core/utils";
 import { blueprintShape } from "./upgrades";
 import { globalConfig } from "../core/config";
@@ -20,11 +20,11 @@ export class Blueprint {
 
     /**
      * Returns the layer of this blueprint
-     * @returns {enumLayer}
+     * @returns {Layer}
      */
     get layer() {
         if (this.entities.length === 0) {
-            return enumLayer.regular;
+            return "regular";
         }
         return this.entities[0].layer;
     }
diff --git a/src/js/game/buildings/belt_base.js b/src/js/game/buildings/belt_base.js
index 059591ce..1aafa9e1 100644
--- a/src/js/game/buildings/belt_base.js
+++ b/src/js/game/buildings/belt_base.js
@@ -89,7 +89,7 @@ export class MetaBeltBaseBuilding extends MetaBuilding {
      * @param {Vector} param0.tile
      * @param {number} param0.rotation
      * @param {string} param0.variant
-     * @param {string} param0.layer
+     * @param {Layer} param0.layer
      * @return {{ rotation: number, rotationVariant: number, connectedEntities?: Array<Entity> }}
      */
     computeOptimalDirectionAndRotationVariantAtTile({ root, tile, rotation, variant, layer }) {
diff --git a/src/js/game/buildings/constant_signal.js b/src/js/game/buildings/constant_signal.js
index 5c88248f..93e0ab36 100644
--- a/src/js/game/buildings/constant_signal.js
+++ b/src/js/game/buildings/constant_signal.js
@@ -2,7 +2,7 @@ import { enumDirection, Vector } from "../../core/vector";
 import { enumPinSlotType, WiredPinsComponent } from "../components/wired_pins";
 import { Entity } from "../entity";
 import { MetaBuilding } from "../meta_building";
-import { enumLayer, GameRoot } from "../root";
+import { GameRoot } from "../root";
 import { ConstantSignalComponent } from "../components/constant_signal";
 
 export class MetaConstantSignalBuilding extends MetaBuilding {
@@ -22,8 +22,9 @@ export class MetaConstantSignalBuilding extends MetaBuilding {
         return true;
     }
 
+    /** @returns {"wires"} **/
     getLayer() {
-        return enumLayer.wires;
+        return "wires";
     }
 
     getDimensions() {
diff --git a/src/js/game/buildings/cutter.js b/src/js/game/buildings/cutter.js
index bfe142d5..739f4a05 100644
--- a/src/js/game/buildings/cutter.js
+++ b/src/js/game/buildings/cutter.js
@@ -8,7 +8,6 @@ import { Entity } from "../entity";
 import { defaultBuildingVariant, MetaBuilding } from "../meta_building";
 import { GameRoot } from "../root";
 import { enumHubGoalRewards } from "../tutorial_goals";
-import { enumItemType } from "../base_item";
 
 /** @enum {string} */
 export const enumCutterVariants = { quad: "quad" };
@@ -82,7 +81,7 @@ export class MetaCutterBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                 ],
             })
diff --git a/src/js/game/buildings/hub.js b/src/js/game/buildings/hub.js
index c11c9197..b9929b31 100644
--- a/src/js/game/buildings/hub.js
+++ b/src/js/game/buildings/hub.js
@@ -1,5 +1,4 @@
 import { enumDirection, Vector } from "../../core/vector";
-import { enumItemType } from "../base_item";
 import { HubComponent } from "../components/hub";
 import { ItemAcceptorComponent } from "../components/item_acceptor";
 import { enumItemProcessorTypes, ItemProcessorComponent } from "../components/item_processor";
@@ -68,72 +67,72 @@ export class MetaHubBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.top, enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [enumDirection.top],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(2, 0),
                         directions: [enumDirection.top],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(3, 0),
                         directions: [enumDirection.top, enumDirection.right],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(0, 3),
                         directions: [enumDirection.bottom, enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(1, 3),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(2, 3),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(3, 3),
                         directions: [enumDirection.bottom, enumDirection.right],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(0, 1),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(0, 2),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(0, 3),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(3, 1),
                         directions: [enumDirection.right],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(3, 2),
                         directions: [enumDirection.right],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(3, 3),
                         directions: [enumDirection.right],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                 ],
             })
diff --git a/src/js/game/buildings/logic_gate.js b/src/js/game/buildings/logic_gate.js
index bc9c7777..e07db3ea 100644
--- a/src/js/game/buildings/logic_gate.js
+++ b/src/js/game/buildings/logic_gate.js
@@ -2,7 +2,7 @@ import { enumDirection, Vector } from "../../core/vector";
 import { enumPinSlotType, WiredPinsComponent } from "../components/wired_pins";
 import { Entity } from "../entity";
 import { MetaBuilding, defaultBuildingVariant } from "../meta_building";
-import { enumLayer, GameRoot } from "../root";
+import { GameRoot } from "../root";
 import { enumLogicGateType, LogicGateComponent } from "../components/logic_gate";
 
 /** @enum {string} */
@@ -39,8 +39,9 @@ export class MetaLogicGateBuilding extends MetaBuilding {
         return true;
     }
 
+    /** @returns {"wires"} **/
     getLayer() {
-        return enumLayer.wires;
+        return "wires";
     }
 
     getDimensions() {
diff --git a/src/js/game/buildings/mixer.js b/src/js/game/buildings/mixer.js
index a2b35280..cbde309e 100644
--- a/src/js/game/buildings/mixer.js
+++ b/src/js/game/buildings/mixer.js
@@ -1,7 +1,6 @@
 import { formatItemsPerSecond } from "../../core/utils";
 import { enumDirection, Vector } from "../../core/vector";
 import { T } from "../../translations";
-import { enumItemType } from "../base_item";
 import { ItemAcceptorComponent } from "../components/item_acceptor";
 import { ItemEjectorComponent } from "../components/item_ejector";
 import { enumItemProcessorTypes, ItemProcessorComponent } from "../components/item_processor";
@@ -63,12 +62,12 @@ export class MetaMixerBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                 ],
             })
diff --git a/src/js/game/buildings/painter.js b/src/js/game/buildings/painter.js
index 61e77a7c..49c2ff69 100644
--- a/src/js/game/buildings/painter.js
+++ b/src/js/game/buildings/painter.js
@@ -8,7 +8,6 @@ import { Entity } from "../entity";
 import { defaultBuildingVariant, MetaBuilding } from "../meta_building";
 import { GameRoot } from "../root";
 import { enumHubGoalRewards } from "../tutorial_goals";
-import { enumItemType } from "../base_item";
 
 /** @enum {string} */
 export const enumPainterVariants = { mirrored: "mirrored", double: "double", quad: "quad" };
@@ -98,12 +97,12 @@ export class MetaPainterBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [enumDirection.top],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                 ],
             })
@@ -124,14 +123,14 @@ export class MetaPainterBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [
                             variant === defaultBuildingVariant ? enumDirection.top : enumDirection.bottom,
                         ],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                 ]);
 
@@ -147,17 +146,17 @@ export class MetaPainterBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(0, 1),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [enumDirection.top],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                 ]);
 
@@ -174,27 +173,27 @@ export class MetaPainterBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.left],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                     {
                         pos: new Vector(2, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                     {
                         pos: new Vector(3, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.color,
+                        filter: "color",
                     },
                 ]);
 
diff --git a/src/js/game/buildings/rotater.js b/src/js/game/buildings/rotater.js
index 45bb97b9..c278ef0d 100644
--- a/src/js/game/buildings/rotater.js
+++ b/src/js/game/buildings/rotater.js
@@ -8,7 +8,6 @@ import { Entity } from "../entity";
 import { defaultBuildingVariant, MetaBuilding } from "../meta_building";
 import { GameRoot } from "../root";
 import { enumHubGoalRewards } from "../tutorial_goals";
-import { enumItemType } from "../base_item";
 
 /** @enum {string} */
 export const enumRotaterVariants = { ccw: "ccw", fl: "fl" };
@@ -89,7 +88,7 @@ export class MetaRotaterBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                 ],
             })
diff --git a/src/js/game/buildings/stacker.js b/src/js/game/buildings/stacker.js
index 91ac3f62..40a9c5ae 100644
--- a/src/js/game/buildings/stacker.js
+++ b/src/js/game/buildings/stacker.js
@@ -8,7 +8,6 @@ import { Entity } from "../entity";
 import { MetaBuilding } from "../meta_building";
 import { GameRoot } from "../root";
 import { enumHubGoalRewards } from "../tutorial_goals";
-import { enumItemType } from "../base_item";
 
 export class MetaStackerBuilding extends MetaBuilding {
     constructor() {
@@ -63,12 +62,12 @@ export class MetaStackerBuilding extends MetaBuilding {
                     {
                         pos: new Vector(0, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                     {
                         pos: new Vector(1, 0),
                         directions: [enumDirection.bottom],
-                        filter: enumItemType.shape,
+                        filter: "shape",
                     },
                 ],
             })
diff --git a/src/js/game/buildings/underground_belt.js b/src/js/game/buildings/underground_belt.js
index 4b647c13..155b69e2 100644
--- a/src/js/game/buildings/underground_belt.js
+++ b/src/js/game/buildings/underground_belt.js
@@ -5,7 +5,7 @@ import { ItemEjectorComponent } from "../components/item_ejector";
 import { enumUndergroundBeltMode, UndergroundBeltComponent } from "../components/underground_belt";
 import { Entity } from "../entity";
 import { MetaBuilding, defaultBuildingVariant } from "../meta_building";
-import { GameRoot, enumLayer } from "../root";
+import { GameRoot } from "../root";
 import { globalConfig } from "../../core/config";
 import { enumHubGoalRewards } from "../tutorial_goals";
 import { formatItemsPerSecond, generateMatrixRotations } from "../../core/utils";
@@ -171,7 +171,7 @@ export class MetaUndergroundBeltBuilding extends MetaBuilding {
      * @param {Vector} param0.tile
      * @param {number} param0.rotation
      * @param {string} param0.variant
-     * @param {string} param0.layer
+     * @param {Layer} param0.layer
      * @return {{ rotation: number, rotationVariant: number, connectedEntities?: Array<Entity> }}
      */
     computeOptimalDirectionAndRotationVariantAtTile({ root, tile, rotation, variant, layer }) {
@@ -190,7 +190,7 @@ export class MetaUndergroundBeltBuilding extends MetaBuilding {
             tile = tile.addScalars(searchVector.x, searchVector.y);
 
             /* WIRES: FIXME */
-            const contents = root.map.getTileContent(tile, enumLayer.regular);
+            const contents = root.map.getTileContent(tile, "regular");
             if (contents) {
                 const undergroundComp = contents.components.UndergroundBelt;
                 if (undergroundComp && undergroundComp.tier === tier) {
diff --git a/src/js/game/buildings/wire.js b/src/js/game/buildings/wire.js
index fa6e23a3..59c9cb7d 100644
--- a/src/js/game/buildings/wire.js
+++ b/src/js/game/buildings/wire.js
@@ -5,7 +5,7 @@ import { SOUNDS } from "../../platform/sound";
 import { enumWireType, WireComponent } from "../components/wire";
 import { Entity } from "../entity";
 import { MetaBuilding } from "../meta_building";
-import { enumLayer, GameRoot } from "../root";
+import { GameRoot } from "../root";
 
 export const arrayWireRotationVariantToType = [
     enumWireType.regular,
@@ -50,8 +50,9 @@ export class MetaWireBuilding extends MetaBuilding {
         return true;
     }
 
+    /** @returns {"wires"} **/
     getLayer() {
-        return enumLayer.wires;
+        return "wires";
     }
 
     getSprite() {
diff --git a/src/js/game/buildings/wire_tunnel.js b/src/js/game/buildings/wire_tunnel.js
index 80ab8799..f885abc6 100644
--- a/src/js/game/buildings/wire_tunnel.js
+++ b/src/js/game/buildings/wire_tunnel.js
@@ -1,7 +1,7 @@
 import { Vector } from "../../core/vector";
 import { Entity } from "../entity";
 import { MetaBuilding, defaultBuildingVariant } from "../meta_building";
-import { GameRoot, enumLayer } from "../root";
+import { GameRoot } from "../root";
 import { WireTunnelComponent } from "../components/wire_tunnel";
 import { generateMatrixRotations } from "../../core/utils";
 
@@ -55,8 +55,9 @@ export class MetaWireTunnelBuilding extends MetaBuilding {
         return [defaultBuildingVariant, enumWireTunnelVariants.coating];
     }
 
+    /** @returns {"wires"} **/
     getLayer() {
-        return enumLayer.wires;
+        return "wires";
     }
 
     getRotateAutomaticallyWhilePlacing() {
diff --git a/src/js/game/components/item_acceptor.js b/src/js/game/components/item_acceptor.js
index d4fdaf72..ebd7ae5f 100644
--- a/src/js/game/components/item_acceptor.js
+++ b/src/js/game/components/item_acceptor.js
@@ -1,12 +1,12 @@
 import { enumDirection, enumInvertedDirections, Vector } from "../../core/vector";
 import { types } from "../../savegame/serialization";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 import { Component } from "../component";
 
 /** @typedef {{
  * pos: Vector,
  * directions: enumDirection[],
- * filter?: enumItemType
+ * filter?: ItemType
  * }} ItemAcceptorSlot */
 
 /**
@@ -20,7 +20,7 @@ import { Component } from "../component";
 /** @typedef {{
  * pos: Vector,
  * directions: enumDirection[],
- * filter?: enumItemType
+ * filter?: ItemType
  * }} ItemAcceptorSlotConfig */
 
 export class ItemAcceptorComponent extends Component {
@@ -74,7 +74,7 @@ export class ItemAcceptorComponent extends Component {
                 pos: slot.pos,
                 directions: slot.directions,
 
-                // Which type of item to accept (shape | color | all) @see enumItemType
+                // Which type of item to accept (shape | color | all) @see ItemType
                 filter: slot.filter,
             });
         }
diff --git a/src/js/game/components/storage.js b/src/js/game/components/storage.js
index 34e51f4b..3b32f6a3 100644
--- a/src/js/game/components/storage.js
+++ b/src/js/game/components/storage.js
@@ -1,5 +1,5 @@
 import { types } from "../../savegame/serialization";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 import { Component } from "../component";
 import { typeItemSingleton } from "../item_resolver";
 import { ColorItem } from "../items/color_item";
@@ -65,11 +65,11 @@ export class StorageComponent extends Component {
             return false;
         }
 
-        if (itemType === enumItemType.color) {
+        if (itemType === "color") {
             return /** @type {ColorItem} */ (this.storedItem).color === /** @type {ColorItem} */ (item).color;
         }
 
-        if (itemType === enumItemType.shape) {
+        if (itemType === "shape") {
             return (
                 /** @type {ShapeItem} */ (this.storedItem).definition.getHash() ===
                 /** @type {ShapeItem} */ (item).definition.getHash()
diff --git a/src/js/game/core.js b/src/js/game/core.js
index 0a8aaf7a..70d69c2c 100644
--- a/src/js/game/core.js
+++ b/src/js/game/core.js
@@ -26,7 +26,7 @@ import { GameLogic } from "./logic";
 import { MapView } from "./map_view";
 import { defaultBuildingVariant } from "./meta_building";
 import { ProductionAnalytics } from "./production_analytics";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 import { ShapeDefinitionManager } from "./shape_definition_manager";
 import { SoundProxy } from "./sound_proxy";
 import { GameTime } from "./time/game_time";
@@ -411,7 +411,7 @@ export class GameCore {
             // Green wires overlay
             root.hud.parts.wiresOverlay.draw(params);
 
-            if (this.root.currentLayer === enumLayer.wires) {
+            if (this.root.currentLayer === "wires") {
                 // Static map entities
                 root.map.drawWiresForegroundLayer(params);
 
diff --git a/src/js/game/entity.js b/src/js/game/entity.js
index d3a53e90..ca21a16d 100644
--- a/src/js/game/entity.js
+++ b/src/js/game/entity.js
@@ -3,7 +3,7 @@ import { DrawParameters } from "../core/draw_parameters";
 import { Component } from "./component";
 /* typehints:end */
 
-import { GameRoot, enumLayer } from "./root";
+import { GameRoot } from "./root";
 import { globalConfig } from "../core/config";
 import { enumDirectionToVector, enumDirectionToAngle } from "../core/vector";
 import { BasicSerializableObject, types } from "../savegame/serialization";
@@ -36,8 +36,9 @@ export class Entity extends BasicSerializableObject {
 
         /**
          * On which layer this entity is
+         * @type {Layer}
          */
-        this.layer = enumLayer.regular;
+        this.layer = "regular";
 
         /**
          * Internal entity unique id, set by the @see EntityManager
diff --git a/src/js/game/hub_goals.js b/src/js/game/hub_goals.js
index d946ce51..8adee905 100644
--- a/src/js/game/hub_goals.js
+++ b/src/js/game/hub_goals.js
@@ -3,7 +3,7 @@ import { clamp, findNiceIntegerValue, randomChoice, randomInt } from "../core/ut
 import { BasicSerializableObject, types } from "../savegame/serialization";
 import { enumColors } from "./colors";
 import { enumItemProcessorTypes } from "./components/item_processor";
-import { GameRoot, enumLayer } from "./root";
+import { GameRoot } from "./root";
 import { enumSubShape, ShapeDefinition } from "./shape_definition";
 import { enumHubGoalRewards, tutorialGoals } from "./tutorial_goals";
 import { UPGRADES } from "./upgrades";
diff --git a/src/js/game/hud/parts/blueprint_placer.js b/src/js/game/hud/parts/blueprint_placer.js
index 38341395..47bf1363 100644
--- a/src/js/game/hud/parts/blueprint_placer.js
+++ b/src/js/game/hud/parts/blueprint_placer.js
@@ -11,7 +11,6 @@ import { BaseHUDPart } from "../base_hud_part";
 import { DynamicDomAttach } from "../dynamic_dom_attach";
 import { Blueprint } from "../../blueprint";
 import { SOUNDS } from "../../../platform/sound";
-import { enumLayer } from "../../root";
 
 export class HUDBlueprintPlacer extends BaseHUDPart {
     createElements(parent) {
@@ -60,7 +59,7 @@ export class HUDBlueprintPlacer extends BaseHUDPart {
 
     /**
      * Called when the layer was changed
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      */
     onEditModeChanged(layer) {
         // Check if the layer of the blueprint differs and thus we have to deselect it
diff --git a/src/js/game/hud/parts/building_placer.js b/src/js/game/hud/parts/building_placer.js
index a3d87dc6..013fcde4 100644
--- a/src/js/game/hud/parts/building_placer.js
+++ b/src/js/game/hud/parts/building_placer.js
@@ -18,7 +18,7 @@ import { THEME } from "../../theme";
 import { DynamicDomAttach } from "../dynamic_dom_attach";
 import { HUDBuildingPlacerLogic } from "./building_placer_logic";
 import { makeOffscreenBuffer } from "../../../core/buffer_utils";
-import { enumLayer } from "../../root";
+import { layers } from "../../root";
 import { getCodeFromBuildingData } from "../../building_codes";
 
 export class HUDBuildingPlacer extends HUDBuildingPlacerLogic {
@@ -61,9 +61,9 @@ export class HUDBuildingPlacer extends HUDBuildingPlacerLogic {
         this.currentInterpolatedCornerTile = new Vector();
 
         this.lockIndicatorSprites = {};
-        for (const layerId in enumLayer) {
-            this.lockIndicatorSprites[layerId] = this.makeLockIndicatorSprite(layerId);
-        }
+        layers.forEach(layer => {
+            this.lockIndicatorSprites[layer] = this.makeLockIndicatorSprite(layer);
+        });
 
         //
 
@@ -76,7 +76,7 @@ export class HUDBuildingPlacer extends HUDBuildingPlacerLogic {
 
     /**
      * Makes the lock indicator sprite for the given layer
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      */
     makeLockIndicatorSprite(layer) {
         const dims = 48;
diff --git a/src/js/game/hud/parts/building_placer_logic.js b/src/js/game/hud/parts/building_placer_logic.js
index b010ff40..898801c0 100644
--- a/src/js/game/hud/parts/building_placer_logic.js
+++ b/src/js/game/hud/parts/building_placer_logic.js
@@ -12,7 +12,6 @@ import { BaseHUDPart } from "../base_hud_part";
 import { SOUNDS } from "../../../platform/sound";
 import { MetaMinerBuilding, enumMinerVariants } from "../../buildings/miner";
 import { enumHubGoalRewards } from "../../tutorial_goals";
-import { enumLayer } from "../../root";
 import { getBuildingDataFromCode, getCodeFromBuildingData } from "../../building_codes";
 import { MetaHubBuilding } from "../../buildings/hub";
 
@@ -133,12 +132,12 @@ export class HUDBuildingPlacerLogic extends BaseHUDPart {
 
     /**
      * Called when the edit mode got changed
-     * @param {enumLayer} editMode
+     * @param {Layer} layer
      */
-    onEditModeChanged(editMode) {
+    onEditModeChanged(layer) {
         const metaBuilding = this.currentMetaBuilding.get();
         if (metaBuilding) {
-            if (metaBuilding.getLayer() !== editMode) {
+            if (metaBuilding.getLayer() !== layer) {
                 // This layer doesn't fit the edit mode anymore
                 this.currentMetaBuilding.set(null);
             }
diff --git a/src/js/game/hud/parts/buildings_toolbar.js b/src/js/game/hud/parts/buildings_toolbar.js
index be46f239..8c05ab70 100644
--- a/src/js/game/hud/parts/buildings_toolbar.js
+++ b/src/js/game/hud/parts/buildings_toolbar.js
@@ -8,7 +8,6 @@ import { MetaSplitterBuilding } from "../../buildings/splitter";
 import { MetaStackerBuilding } from "../../buildings/stacker";
 import { MetaTrashBuilding } from "../../buildings/trash";
 import { MetaUndergroundBeltBuilding } from "../../buildings/underground_belt";
-import { enumLayer } from "../../root";
 import { HUDBaseToolbar } from "./base_toolbar";
 import { MetaLeverBuilding } from "../../buildings/lever";
 import { MetaFilterBuilding } from "../../buildings/filter";
@@ -35,7 +34,7 @@ export class HUDBuildingsToolbar extends HUDBaseToolbar {
         super(root, {
             supportedBuildings,
             visibilityCondition: () =>
-                !this.root.camera.getIsMapOverlayActive() && this.root.currentLayer === enumLayer.regular,
+                !this.root.camera.getIsMapOverlayActive() && this.root.currentLayer === "regular",
             htmlElementId: "ingame_HUD_buildings_toolbar",
         });
     }
diff --git a/src/js/game/hud/parts/color_blind_helper.js b/src/js/game/hud/parts/color_blind_helper.js
index 46890979..e5572228 100644
--- a/src/js/game/hud/parts/color_blind_helper.js
+++ b/src/js/game/hud/parts/color_blind_helper.js
@@ -7,8 +7,6 @@ import { DrawParameters } from "../../../core/draw_parameters";
 import { THEME } from "../../theme";
 import { globalConfig } from "../../../core/config";
 import { T } from "../../../translations";
-import { enumItemType } from "../../base_item";
-import { enumLayer } from "../../root";
 
 export class HUDColorBlindHelper extends BaseHUDPart {
     createElements(parent) {
@@ -41,7 +39,7 @@ export class HUDColorBlindHelper extends BaseHUDPart {
             return null;
         }
 
-        if (this.root.currentLayer !== enumLayer.regular) {
+        if (this.root.currentLayer !== "regular") {
             // Not in regular mode
             return null;
         }
@@ -56,7 +54,7 @@ export class HUDColorBlindHelper extends BaseHUDPart {
             // Check if the belt has a color item
             if (beltComp) {
                 const item = beltComp.assignedPath.findItemAtTile(tile);
-                if (item && item.getItemType() === enumItemType.color) {
+                if (item && item.getItemType() === "color") {
                     return /** @type {ColorItem} */ (item).color;
                 }
             }
@@ -66,7 +64,7 @@ export class HUDColorBlindHelper extends BaseHUDPart {
             if (ejectorComp) {
                 for (let i = 0; i < ejectorComp.slots.length; ++i) {
                     const slot = ejectorComp.slots[i];
-                    if (slot.item && slot.item.getItemType() === enumItemType.color) {
+                    if (slot.item && slot.item.getItemType() === "color") {
                         return /** @type {ColorItem} */ (slot.item).color;
                     }
                 }
@@ -74,7 +72,7 @@ export class HUDColorBlindHelper extends BaseHUDPart {
         } else {
             // We hovered a lower layer, show the color there
             const lowerLayer = this.root.map.getLowerLayerContentXY(tile.x, tile.y);
-            if (lowerLayer && lowerLayer.getItemType() === enumItemType.color) {
+            if (lowerLayer && lowerLayer.getItemType() === "color") {
                 return /** @type {ColorItem} */ (lowerLayer).color;
             }
         }
diff --git a/src/js/game/hud/parts/layer_preview.js b/src/js/game/hud/parts/layer_preview.js
index cc66a817..36e0ea58 100644
--- a/src/js/game/hud/parts/layer_preview.js
+++ b/src/js/game/hud/parts/layer_preview.js
@@ -3,7 +3,6 @@ import { globalConfig } from "../../../core/config";
 import { Loader } from "../../../core/loader";
 import { Vector } from "../../../core/vector";
 import { MapChunkView } from "../../map_chunk_view";
-import { enumLayer } from "../../root";
 import { THEME } from "../../theme";
 import { BaseHUDPart } from "../base_hud_part";
 
@@ -76,7 +75,7 @@ export class HUDLayerPreview extends BaseHUDPart {
                 const tileX = dx + startTileX;
                 const tileY = dy + startTileY;
 
-                const content = this.root.map.getLayerContentXY(tileX, tileY, enumLayer.wires);
+                const content = this.root.map.getLayerContentXY(tileX, tileY, "wires");
                 if (content) {
                     MapChunkView.drawSingleWiresOverviewTile({
                         context: this.context,
@@ -104,7 +103,7 @@ export class HUDLayerPreview extends BaseHUDPart {
      * @param {number} scale 1 / zoomLevel
      */
     renderPreview(parameters, worldPos, scale) {
-        if (this.root.currentLayer !== enumLayer.regular) {
+        if (this.root.currentLayer !== "regular") {
             // Only supporting wires right now
             return;
         }
diff --git a/src/js/game/hud/parts/lever_toggle.js b/src/js/game/hud/parts/lever_toggle.js
index 8458022f..1859f7ab 100644
--- a/src/js/game/hud/parts/lever_toggle.js
+++ b/src/js/game/hud/parts/lever_toggle.js
@@ -1,7 +1,6 @@
 import { STOP_PROPAGATION } from "../../../core/signal";
 import { Vector } from "../../../core/vector";
 import { enumMouseButton } from "../../camera";
-import { enumLayer } from "../../root";
 import { BaseHUDPart } from "../base_hud_part";
 
 export class HUDLeverToggle extends BaseHUDPart {
@@ -15,7 +14,7 @@ export class HUDLeverToggle extends BaseHUDPart {
      */
     downPreHandler(pos, button) {
         const tile = this.root.camera.screenToWorld(pos).toTileSpace();
-        const contents = this.root.map.getLayerContentXY(tile.x, tile.y, enumLayer.regular);
+        const contents = this.root.map.getLayerContentXY(tile.x, tile.y, "regular");
         if (contents) {
             const leverComp = contents.components.Lever;
             if (leverComp) {
diff --git a/src/js/game/hud/parts/wire_info.js b/src/js/game/hud/parts/wire_info.js
index a4e03fbb..f73d53d7 100644
--- a/src/js/game/hud/parts/wire_info.js
+++ b/src/js/game/hud/parts/wire_info.js
@@ -1,6 +1,5 @@
 import { globalConfig } from "../../../core/config";
 import { MapChunkView } from "../../map_chunk_view";
-import { enumLayer } from "../../root";
 import { WireNetwork } from "../../systems/wire";
 import { THEME } from "../../theme";
 import { BaseHUDPart } from "../base_hud_part";
@@ -17,7 +16,7 @@ export class HUDWireInfo extends BaseHUDPart {
      * @param {import("../../../core/draw_utils").DrawParameters} parameters
      */
     drawOverlays(parameters) {
-        if (this.root.currentLayer !== enumLayer.wires) {
+        if (this.root.currentLayer !== "wires") {
             // Not in the wires layer
             return;
         }
@@ -30,7 +29,7 @@ export class HUDWireInfo extends BaseHUDPart {
 
         const worldPos = this.root.camera.screenToWorld(mousePos);
         const tile = worldPos.toTileSpace();
-        const entity = this.root.map.getLayerContentXY(tile.x, tile.y, enumLayer.wires);
+        const entity = this.root.map.getLayerContentXY(tile.x, tile.y, "wires");
 
         if (!entity) {
             // No entity
diff --git a/src/js/game/hud/parts/wires_overlay.js b/src/js/game/hud/parts/wires_overlay.js
index 10652e11..364002fd 100644
--- a/src/js/game/hud/parts/wires_overlay.js
+++ b/src/js/game/hud/parts/wires_overlay.js
@@ -2,7 +2,6 @@ import { makeOffscreenBuffer } from "../../../core/buffer_utils";
 import { globalConfig } from "../../../core/config";
 import { DrawParameters } from "../../../core/draw_parameters";
 import { KEYMAPPINGS } from "../../key_action_mapper";
-import { enumLayer } from "../../root";
 import { THEME } from "../../theme";
 import { BaseHUDPart } from "../base_hud_part";
 import { Loader } from "../../../core/loader";
@@ -26,10 +25,10 @@ export class HUDWiresOverlay extends BaseHUDPart {
      * Switches between layers
      */
     switchLayers() {
-        if (this.root.currentLayer === enumLayer.regular) {
-            this.root.currentLayer = enumLayer.wires;
+        if (this.root.currentLayer === "regular") {
+            this.root.currentLayer = "wires";
         } else {
-            this.root.currentLayer = enumLayer.regular;
+            this.root.currentLayer = "regular";
         }
         this.root.signals.editModeChanged.dispatch(this.root.currentLayer);
     }
@@ -51,7 +50,7 @@ export class HUDWiresOverlay extends BaseHUDPart {
     }
 
     update() {
-        const desiredAlpha = this.root.currentLayer === enumLayer.wires ? 1.0 : 0.0;
+        const desiredAlpha = this.root.currentLayer === "wires" ? 1.0 : 0.0;
         this.currentAlpha = lerp(this.currentAlpha, desiredAlpha, 0.12);
     }
 
diff --git a/src/js/game/hud/parts/wires_toolbar.js b/src/js/game/hud/parts/wires_toolbar.js
index 35ed21e8..542218e2 100644
--- a/src/js/game/hud/parts/wires_toolbar.js
+++ b/src/js/game/hud/parts/wires_toolbar.js
@@ -1,4 +1,3 @@
-import { enumLayer } from "../../root";
 import { HUDBaseToolbar } from "./base_toolbar";
 import { MetaWireBuilding } from "../../buildings/wire";
 import { MetaConstantSignalBuilding } from "../../buildings/constant_signal";
@@ -19,7 +18,7 @@ export class HUDWiresToolbar extends HUDBaseToolbar {
         super(root, {
             supportedBuildings,
             visibilityCondition: () =>
-                !this.root.camera.getIsMapOverlayActive() && this.root.currentLayer === enumLayer.wires,
+                !this.root.camera.getIsMapOverlayActive() && this.root.currentLayer === "wires",
             htmlElementId: "ingame_HUD_wires_toolbar",
         });
     }
diff --git a/src/js/game/hud/trailer_maker.js b/src/js/game/hud/trailer_maker.js
index cb81aab3..8655def4 100644
--- a/src/js/game/hud/trailer_maker.js
+++ b/src/js/game/hud/trailer_maker.js
@@ -1,4 +1,4 @@
-import { GameRoot, enumLayer } from "../root";
+import { GameRoot } from "../root";
 import { globalConfig } from "../../core/config";
 import { Vector, mixVector } from "../../core/vector";
 import { lerp } from "../../core/utils";
diff --git a/src/js/game/items/boolean_item.js b/src/js/game/items/boolean_item.js
index 971defc5..57342bde 100644
--- a/src/js/game/items/boolean_item.js
+++ b/src/js/game/items/boolean_item.js
@@ -1,7 +1,7 @@
 import { DrawParameters } from "../../core/draw_parameters";
 import { Loader } from "../../core/loader";
 import { types } from "../../savegame/serialization";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 
 export class BooleanItem extends BaseItem {
     static getId() {
@@ -20,8 +20,9 @@ export class BooleanItem extends BaseItem {
         this.value = data;
     }
 
+    /** @returns {"boolean"} **/
     getItemType() {
-        return enumItemType.boolean;
+        return "boolean";
     }
 
     /**
diff --git a/src/js/game/items/color_item.js b/src/js/game/items/color_item.js
index c62e6f6b..76a1e1d0 100644
--- a/src/js/game/items/color_item.js
+++ b/src/js/game/items/color_item.js
@@ -2,7 +2,7 @@ import { globalConfig } from "../../core/config";
 import { smoothenDpi } from "../../core/dpi_manager";
 import { DrawParameters } from "../../core/draw_parameters";
 import { types } from "../../savegame/serialization";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 import { enumColors, enumColorsToHexCode } from "../colors";
 import { THEME } from "../theme";
 
@@ -23,8 +23,9 @@ export class ColorItem extends BaseItem {
         this.color = data;
     }
 
+    /** @returns {"color"} **/
     getItemType() {
-        return enumItemType.color;
+        return "color";
     }
 
     /**
diff --git a/src/js/game/items/shape_item.js b/src/js/game/items/shape_item.js
index 7248c581..44081cab 100644
--- a/src/js/game/items/shape_item.js
+++ b/src/js/game/items/shape_item.js
@@ -1,6 +1,6 @@
 import { DrawParameters } from "../../core/draw_parameters";
 import { types } from "../../savegame/serialization";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 import { ShapeDefinition } from "../shape_definition";
 import { THEME } from "../theme";
 
@@ -21,8 +21,9 @@ export class ShapeItem extends BaseItem {
         this.definition = ShapeDefinition.fromShortKey(data);
     }
 
+    /** @returns {"shape"} **/
     getItemType() {
-        return enumItemType.shape;
+        return "shape";
     }
 
     /**
diff --git a/src/js/game/logic.js b/src/js/game/logic.js
index 48e47c3a..ce4d18a5 100644
--- a/src/js/game/logic.js
+++ b/src/js/game/logic.js
@@ -5,7 +5,7 @@ import { enumDirection, enumDirectionToVector, enumInvertedDirections, Vector }
 import { getBuildingDataFromCode } from "./building_codes";
 import { Entity } from "./entity";
 import { MetaBuilding } from "./meta_building";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 import { WireNetwork } from "./systems/wire";
 import { globalConfig } from "../core/config";
 import { CHUNK_OVERLAY_RES } from "./map_chunk_view";
@@ -347,7 +347,7 @@ export class GameLogic {
         }
 
         // Now check if there's a connectable wire
-        const targetEntity = this.root.map.getTileContent(tile, enumLayer.wires);
+        const targetEntity = this.root.map.getTileContent(tile, "wires");
         if (!targetEntity) {
             return enumWireEdgeFlag.empty;
         }
@@ -401,7 +401,7 @@ export class GameLogic {
                     continue;
                 }
 
-                const entity = this.root.map.getLayerContentXY(tile.x + dx, tile.y + dy, enumLayer.regular);
+                const entity = this.root.map.getLayerContentXY(tile.x + dx, tile.y + dy, "regular");
                 if (entity) {
                     let ejectorSlots = [];
                     let acceptorSlots = [];
diff --git a/src/js/game/map.js b/src/js/game/map.js
index f818bc46..5ff51ce8 100644
--- a/src/js/game/map.js
+++ b/src/js/game/map.js
@@ -4,7 +4,7 @@ import { BasicSerializableObject, types } from "../savegame/serialization";
 import { BaseItem } from "./base_item";
 import { Entity } from "./entity";
 import { MapChunkView } from "./map_chunk_view";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 
 export class BaseMap extends BasicSerializableObject {
     static getId() {
@@ -94,7 +94,7 @@ export class BaseMap extends BasicSerializableObject {
     /**
      * Returns the tile content of a given tile
      * @param {Vector} tile
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      * @returns {Entity} Entity or null
      */
     getTileContent(tile, layer) {
@@ -119,7 +119,7 @@ export class BaseMap extends BasicSerializableObject {
      * Returns the tile content of a given tile
      * @param {number} x
      * @param {number} y
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      * @returns {Entity} Entity or null
      */
     getLayerContentXY(x, y, layer) {
@@ -144,7 +144,7 @@ export class BaseMap extends BasicSerializableObject {
     /**
      * Checks if the tile is used
      * @param {Vector} tile
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      * @returns {boolean}
      */
     isTileUsed(tile, layer) {
@@ -159,7 +159,7 @@ export class BaseMap extends BasicSerializableObject {
      * Checks if the tile is used
      * @param {number} x
      * @param {number} y
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      * @returns {boolean}
      */
     isTileUsedXY(x, y, layer) {
diff --git a/src/js/game/map_chunk.js b/src/js/game/map_chunk.js
index 19fd73b4..54af1125 100644
--- a/src/js/game/map_chunk.js
+++ b/src/js/game/map_chunk.js
@@ -7,7 +7,7 @@ import { BaseItem } from "./base_item";
 import { enumColors } from "./colors";
 import { Entity } from "./entity";
 import { COLOR_ITEM_SINGLETONS } from "./items/color_item";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 import { enumSubShape } from "./shape_definition";
 import { Rectangle } from "../core/rectangle";
 
@@ -70,11 +70,11 @@ export class MapChunk {
 
         /**
          * Which entities this chunk contains, sorted by layer
-         * @type {Object<string, Array<Entity>>}
+         * @type {Record<Layer, Array<Entity>>}
          */
         this.containedEntitiesByLayer = {
-            [enumLayer.regular]: [],
-            [enumLayer.wires]: [],
+            regular: [],
+            wires: [],
         };
 
         /**
@@ -362,7 +362,7 @@ export class MapChunk {
      * Returns the contents of this chunk from the given world space coordinates
      * @param {number} worldX
      * @param {number} worldY
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      * @returns {Entity=}
      */
     getLayerContentFromWorldCoords(worldX, worldY, layer) {
@@ -372,7 +372,7 @@ export class MapChunk {
         assert(localY >= 0, "Local Y is < 0");
         assert(localX < globalConfig.mapChunkSize, "Local X is >= chunk size");
         assert(localY < globalConfig.mapChunkSize, "Local Y is >= chunk size");
-        if (layer === enumLayer.regular) {
+        if (layer === "regular") {
             return this.contents[localX][localY] || null;
         } else {
             return this.wireContents[localX][localY] || null;
@@ -425,7 +425,7 @@ export class MapChunk {
      * @param {number} tileX
      * @param {number} tileY
      * @param {Entity=} contents
-     * @param {enumLayer} layer
+     * @param {Layer} layer
      */
     setLayerContentFromWorldCords(tileX, tileY, contents, layer) {
         const localX = tileX - this.tileX;
@@ -436,7 +436,7 @@ export class MapChunk {
         assert(localY < globalConfig.mapChunkSize, "Local Y is >= chunk size");
 
         let oldContents;
-        if (layer === enumLayer.regular) {
+        if (layer === "regular") {
             oldContents = this.contents[localX][localY];
         } else {
             oldContents = this.wireContents[localX][localY];
@@ -450,7 +450,7 @@ export class MapChunk {
             fastArrayDeleteValueIfContained(this.containedEntitiesByLayer[layer], oldContents);
         }
 
-        if (layer === enumLayer.regular) {
+        if (layer === "regular") {
             this.contents[localX][localY] = contents;
         } else {
             this.wireContents[localX][localY] = contents;
diff --git a/src/js/game/map_chunk_view.js b/src/js/game/map_chunk_view.js
index f7ce1064..c62a3401 100644
--- a/src/js/game/map_chunk_view.js
+++ b/src/js/game/map_chunk_view.js
@@ -3,7 +3,7 @@ import { DrawParameters } from "../core/draw_parameters";
 import { getBuildingDataFromCode } from "./building_codes";
 import { Entity } from "./entity";
 import { MapChunk } from "./map_chunk";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 import { THEME } from "./theme";
 import { drawSpriteClipped } from "../core/draw_utils";
 
@@ -91,7 +91,7 @@ export class MapChunkView extends MapChunk {
         parameters.context.imageSmoothingEnabled = true;
 
         // Draw patch items
-        if (this.root.currentLayer === enumLayer.regular) {
+        if (this.root.currentLayer === "regular") {
             for (let i = 0; i < this.patches.length; ++i) {
                 const patch = this.patches[i];
 
@@ -193,7 +193,7 @@ export class MapChunkView extends MapChunk {
             }
         }
 
-        if (this.root.currentLayer === enumLayer.wires) {
+        if (this.root.currentLayer === "wires") {
             // Draw wires overlay
 
             context.fillStyle = THEME.map.wires.overlayColor;
diff --git a/src/js/game/meta_building.js b/src/js/game/meta_building.js
index 21189d22..b09e901e 100644
--- a/src/js/game/meta_building.js
+++ b/src/js/game/meta_building.js
@@ -4,7 +4,7 @@ import { Vector } from "../core/vector";
 import { SOUNDS } from "../platform/sound";
 import { StaticMapEntityComponent } from "./components/static_map_entity";
 import { Entity } from "./entity";
-import { enumLayer, GameRoot } from "./root";
+import { GameRoot } from "./root";
 import { getCodeFromBuildingData } from "./building_codes";
 
 export const defaultBuildingVariant = "default";
@@ -27,10 +27,10 @@ export class MetaBuilding {
 
     /**
      * Returns the edit layer of the building
-     * @returns {enumLayer}
+     * @returns {Layer}
      */
     getLayer() {
-        return enumLayer.regular;
+        return "regular";
     }
 
     /**
@@ -236,7 +236,7 @@ export class MetaBuilding {
      * @param {Vector} param0.tile
      * @param {number} param0.rotation
      * @param {string} param0.variant
-     * @param {string} param0.layer
+     * @param {Layer} param0.layer
      * @return {{ rotation: number, rotationVariant: number, connectedEntities?: Array<Entity> }}
      */
     computeOptimalDirectionAndRotationVariantAtTile({ root, tile, rotation, variant, layer }) {
diff --git a/src/js/game/production_analytics.js b/src/js/game/production_analytics.js
index 41ec31ae..eda79c83 100644
--- a/src/js/game/production_analytics.js
+++ b/src/js/game/production_analytics.js
@@ -1,7 +1,7 @@
 import { GameRoot } from "./root";
 import { ShapeDefinition } from "./shape_definition";
 import { globalConfig } from "../core/config";
-import { BaseItem, enumItemType } from "./base_item";
+import { BaseItem } from "./base_item";
 import { ShapeItem } from "./items/shape_item";
 import { BasicSerializableObject } from "../savegame/serialization";
 
@@ -53,7 +53,7 @@ export class ProductionAnalytics extends BasicSerializableObject {
      * @param {BaseItem} item
      */
     onItemProduced(item) {
-        if (item.getItemType() === enumItemType.shape) {
+        if (item.getItemType() === "shape") {
             const definition = /** @type {ShapeItem} */ (item).definition;
             const key = definition.getHash();
             const entry = this.history[enumAnalyticsDataSource.produced];
diff --git a/src/js/game/root.js b/src/js/game/root.js
index 3279c693..dfb8025a 100644
--- a/src/js/game/root.js
+++ b/src/js/game/root.js
@@ -1,5 +1,4 @@
 /* eslint-disable no-unused-vars */
-
 import { Signal } from "../core/signal";
 import { RandomNumberGenerator } from "../core/rng";
 import { createLogger } from "../core/logging";
@@ -32,14 +31,8 @@ import { Vector } from "../core/vector";
 
 const logger = createLogger("game/root");
 
-/** @enum {string} */
-export const enumLayer = {
-    regular: "regular",
-    wires: "wires",
-};
-
-/** @type {Array<enumLayer>} */
-export const arrayLayers = [enumLayer.regular, enumLayer.wires];
+/** @type {Array<Layer>} */
+export const layers = ["regular", "wires"];
 
 /**
  * The game root is basically the whole game state at a given point,
@@ -134,8 +127,8 @@ export class GameRoot {
         /** @type {DynamicTickrate} */
         this.dynamicTickrate = null;
 
-        /** @type {enumLayer} */
-        this.currentLayer = enumLayer.regular;
+        /** @type {Layer} */
+        this.currentLayer = "regular";
 
         this.signals = {
             // Entities
@@ -167,7 +160,7 @@ export class GameRoot {
 
             bulkOperationFinished: /** @type {TypedSignal<[]>} */ (new Signal()),
 
-            editModeChanged: /** @type {TypedSignal<[enumLayer]>} */ (new Signal()),
+            editModeChanged: /** @type {TypedSignal<[Layer]>} */ (new Signal()),
 
             // Called to check if an entity can be placed, second parameter is an additional offset.
             // Use to introduce additional placement checks
diff --git a/src/js/game/systems/display.js b/src/js/game/systems/display.js
index dd3493c1..6cdb8622 100644
--- a/src/js/game/systems/display.js
+++ b/src/js/game/systems/display.js
@@ -1,12 +1,11 @@
 import { globalConfig } from "../../core/config";
 import { Loader } from "../../core/loader";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 import { enumColors } from "../colors";
 import { DisplayComponent } from "../components/display";
 import { GameSystemWithFilter } from "../game_system_with_filter";
 import { ColorItem, COLOR_ITEM_SINGLETONS } from "../items/color_item";
 import { MapChunkView } from "../map_chunk_view";
-import { enumLayer } from "../root";
 import { BooleanItem } from "../items/boolean_item";
 
 export class DisplaySystem extends GameSystemWithFilter {
@@ -35,18 +34,18 @@ export class DisplaySystem extends GameSystemWithFilter {
         }
 
         switch (value.getItemType()) {
-            case enumItemType.boolean: {
+            case "boolean": {
                 return /** @type {BooleanItem} */ (value).value
                     ? COLOR_ITEM_SINGLETONS[enumColors.white]
                     : null;
             }
 
-            case enumItemType.color: {
+            case "color": {
                 const item = /**@type {ColorItem} */ (value);
                 return item.color === enumColors.uncolored ? null : item;
             }
 
-            case enumItemType.shape: {
+            case "shape": {
                 return value;
             }
 
@@ -61,7 +60,7 @@ export class DisplaySystem extends GameSystemWithFilter {
      * @param {MapChunkView} chunk
      */
     drawChunk(parameters, chunk) {
-        const contents = chunk.containedEntitiesByLayer[enumLayer.regular];
+        const contents = chunk.containedEntitiesByLayer.regular;
         for (let i = 0; i < contents.length; ++i) {
             const entity = contents[i];
             if (entity && entity.components.Display) {
@@ -77,15 +76,15 @@ export class DisplaySystem extends GameSystemWithFilter {
                 }
 
                 const origin = entity.components.StaticMapEntity.origin;
-                if (value.getItemType() === enumItemType.color) {
+                if (value.getItemType() === "color") {
                     this.displaySprites[/** @type {ColorItem} */ (value).color].drawCachedCentered(
                         parameters,
                         (origin.x + 0.5) * globalConfig.tileSize,
                         (origin.y + 0.5) * globalConfig.tileSize,
                         globalConfig.tileSize
                     );
-                } else if (value.getItemType() === enumItemType.shape) {
-                    value.drawCentered(
+                } else if (value.getItemType() === "shape") {
+                    value.draw(
                         (origin.x + 0.5) * globalConfig.tileSize,
                         (origin.y + 0.5) * globalConfig.tileSize,
                         parameters,
diff --git a/src/js/game/systems/item_acceptor.js b/src/js/game/systems/item_acceptor.js
index 4d06f17e..b67bd867 100644
--- a/src/js/game/systems/item_acceptor.js
+++ b/src/js/game/systems/item_acceptor.js
@@ -5,7 +5,6 @@ import { enumDirectionToVector } from "../../core/vector";
 import { ItemAcceptorComponent } from "../components/item_acceptor";
 import { Entity } from "../entity";
 import { GameSystemWithFilter } from "../game_system_with_filter";
-import { enumLayer } from "../root";
 
 export class ItemAcceptorSystem extends GameSystemWithFilter {
     constructor(root) {
diff --git a/src/js/game/systems/lever.js b/src/js/game/systems/lever.js
index c8ebf1a2..fa727535 100644
--- a/src/js/game/systems/lever.js
+++ b/src/js/game/systems/lever.js
@@ -4,7 +4,6 @@ import { BOOL_TRUE_SINGLETON, BOOL_FALSE_SINGLETON } from "../items/boolean_item
 import { MapChunkView } from "../map_chunk_view";
 import { globalConfig } from "../../core/config";
 import { Loader } from "../../core/loader";
-import { enumLayer } from "../root";
 
 export class LeverSystem extends GameSystemWithFilter {
     constructor(root) {
@@ -32,7 +31,7 @@ export class LeverSystem extends GameSystemWithFilter {
      * @param {MapChunkView} chunk
      */
     drawChunk(parameters, chunk) {
-        const contents = chunk.containedEntitiesByLayer[enumLayer.regular];
+        const contents = chunk.containedEntitiesByLayer.regular;
         for (let i = 0; i < contents.length; ++i) {
             const entity = contents[i];
             if (entity && entity.components.Lever) {
diff --git a/src/js/game/systems/logic_gate.js b/src/js/game/systems/logic_gate.js
index ed20ea69..9fe41250 100644
--- a/src/js/game/systems/logic_gate.js
+++ b/src/js/game/systems/logic_gate.js
@@ -1,6 +1,6 @@
 import { LogicGateComponent, enumLogicGateType } from "../components/logic_gate";
 import { GameSystemWithFilter } from "../game_system_with_filter";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
 import { enumPinSlotType } from "../components/wired_pins";
 import { BOOL_TRUE_SINGLETON, BOOL_FALSE_SINGLETON, BooleanItem } from "../items/boolean_item";
 import { enumItemProcessorTypes } from "../components/item_processor";
@@ -72,7 +72,7 @@ export class LogicGateSystem extends GameSystemWithFilter {
             return BOOL_FALSE_SINGLETON;
         }
 
-        if (itemType === enumItemType.boolean) {
+        if (itemType === "boolean") {
             return /** @type {BooleanItem} */ (param1).value && /** @type {BooleanItem} */ (param2).value
                 ? BOOL_TRUE_SINGLETON
                 : BOOL_FALSE_SINGLETON;
@@ -91,7 +91,7 @@ export class LogicGateSystem extends GameSystemWithFilter {
             return BOOL_TRUE_SINGLETON;
         }
 
-        if (item.getItemType() !== enumItemType.boolean) {
+        if (item.getItemType() !== "boolean") {
             // Not a boolean actually
             return BOOL_FALSE_SINGLETON;
         }
@@ -115,11 +115,11 @@ export class LogicGateSystem extends GameSystemWithFilter {
         }
 
         // Check for the right types
-        if (param1 && param1.getItemType() !== enumItemType.boolean) {
+        if (param1 && param1.getItemType() !== "boolean") {
             return BOOL_FALSE_SINGLETON;
         }
 
-        if (param2 && param2.getItemType() !== enumItemType.boolean) {
+        if (param2 && param2.getItemType() !== "boolean") {
             return BOOL_FALSE_SINGLETON;
         }
 
@@ -144,13 +144,9 @@ export class LogicGateSystem extends GameSystemWithFilter {
         }
 
         const valueParam1 =
-            param1 && param1.getItemType() === enumItemType.boolean
-                ? /** @type {BooleanItem} */ (param1).value
-                : 0;
+            param1 && param1.getItemType() === "boolean" ? /** @type {BooleanItem} */ (param1).value : 0;
         const valueParam2 =
-            param2 && param2.getItemType() === enumItemType.boolean
-                ? /** @type {BooleanItem} */ (param2).value
-                : 0;
+            param2 && param2.getItemType() === "boolean" ? /** @type {BooleanItem} */ (param2).value : 0;
 
         return valueParam1 || valueParam2 ? BOOL_TRUE_SINGLETON : BOOL_FALSE_SINGLETON;
     }
@@ -169,7 +165,7 @@ export class LogicGateSystem extends GameSystemWithFilter {
             return null;
         }
 
-        if (flag.getItemType() !== enumItemType.boolean) {
+        if (flag.getItemType() !== "boolean") {
             // Flag is not a boolean
             return null;
         }
diff --git a/src/js/game/systems/miner.js b/src/js/game/systems/miner.js
index b8fd6b5a..0f1fbc45 100644
--- a/src/js/game/systems/miner.js
+++ b/src/js/game/systems/miner.js
@@ -6,7 +6,6 @@ import { MinerComponent } from "../components/miner";
 import { Entity } from "../entity";
 import { GameSystemWithFilter } from "../game_system_with_filter";
 import { MapChunkView } from "../map_chunk_view";
-import { enumLayer } from "../root";
 
 export class MinerSystem extends GameSystemWithFilter {
     constructor(root) {
@@ -75,7 +74,7 @@ export class MinerSystem extends GameSystemWithFilter {
             const ejectingDirection = staticComp.localDirectionToWorld(ejectingSlot.direction);
 
             const targetTile = ejectingPos.add(enumDirectionToVector[ejectingDirection]);
-            const targetContents = this.root.map.getTileContent(targetTile, enumLayer.regular);
+            const targetContents = this.root.map.getTileContent(targetTile, "regular");
 
             // Check if we are connected to another miner and thus do not eject directly
             if (targetContents) {
diff --git a/src/js/game/systems/underground_belt.js b/src/js/game/systems/underground_belt.js
index 5bbb280c..90d29e50 100644
--- a/src/js/game/systems/underground_belt.js
+++ b/src/js/game/systems/underground_belt.js
@@ -13,7 +13,6 @@ import { enumUndergroundBeltMode, UndergroundBeltComponent } from "../components
 import { Entity } from "../entity";
 import { GameSystemWithFilter } from "../game_system_with_filter";
 import { fastArrayDelete } from "../../core/utils";
-import { enumLayer } from "../root";
 
 const logger = createLogger("tunnels");
 
@@ -298,7 +297,7 @@ export class UndergroundBeltSystem extends GameSystemWithFilter {
         ) {
             currentTile = currentTile.add(searchVector);
 
-            const potentialReceiver = this.root.map.getTileContent(currentTile, enumLayer.regular);
+            const potentialReceiver = this.root.map.getTileContent(currentTile, "regular");
             if (!potentialReceiver) {
                 // Empty tile
                 continue;
diff --git a/src/js/game/systems/wire.js b/src/js/game/systems/wire.js
index 17192093..19a2d8be 100644
--- a/src/js/game/systems/wire.js
+++ b/src/js/game/systems/wire.js
@@ -12,7 +12,8 @@ import {
     enumInvertedDirections,
     Vector,
 } from "../../core/vector";
-import { BaseItem, enumItemType } from "../base_item";
+import { BaseItem } from "../base_item";
+import { BooleanItem } from "../items/boolean_item";
 import { arrayWireRotationVariantToType, MetaWireBuilding } from "../buildings/wire";
 import { getCodeFromBuildingData } from "../building_codes";
 import { enumWireType, WireComponent } from "../components/wire";
@@ -577,17 +578,17 @@ export class WireSystem extends GameSystemWithFilter {
         }
 
         const valueType = value.getItemType();
-        if (valueType === enumItemType.shape) {
+        if (valueType === "shape") {
             return {
                 spriteSet: this.wireSprites.shape,
                 opacity: 1,
             };
-        } else if (valueType === enumItemType.color) {
+        } else if (valueType === "color") {
             return {
                 spriteSet: this.wireSprites.color,
                 opacity: 1,
             };
-        } else if (valueType === enumItemType.boolean) {
+        } else if (valueType === "boolean") {
             return {
                 spriteSet: this.wireSprites.regular,
                 opacity: /** @type {BooleanItem} */ (value).value ? 1 : 0.5,
diff --git a/src/js/game/systems/wired_pins.js b/src/js/game/systems/wired_pins.js
index c4ef1b6e..02e84372 100644
--- a/src/js/game/systems/wired_pins.js
+++ b/src/js/game/systems/wired_pins.js
@@ -5,7 +5,6 @@ import { Vector, enumDirectionToAngle } from "../../core/vector";
 import { enumPinSlotType, WiredPinsComponent } from "../components/wired_pins";
 import { Entity } from "../entity";
 import { GameSystemWithFilter } from "../game_system_with_filter";
-import { enumLayer } from "../root";
 import { STOP_PROPAGATION } from "../../core/signal";
 import { drawRotatedSprite } from "../../core/draw_utils";
 import { GLOBAL_APP } from "../../core/globals";
@@ -38,7 +37,7 @@ export class WiredPinsSystem extends GameSystemWithFilter {
 
         // If this entity is placed on the wires layer, make sure we don't
         // place it above a pin
-        if (entity.layer === enumLayer.wires) {
+        if (entity.layer === "wires") {
             for (let x = rect.x; x < rect.x + rect.w; ++x) {
                 for (let y = rect.y; y < rect.y + rect.h; ++y) {
                     // Find which entities are in same tiles of both layers
@@ -103,7 +102,7 @@ export class WiredPinsSystem extends GameSystemWithFilter {
             }
 
             // Check if there is any entity on that tile (Wired pins are always on the wires layer)
-            const collidingEntity = this.root.map.getLayerContentXY(worldPos.x, worldPos.y, enumLayer.wires);
+            const collidingEntity = this.root.map.getLayerContentXY(worldPos.x, worldPos.y, "wires");
 
             // If there's an entity, and it can't get removed -> That's a collision
             if (collidingEntity) {
@@ -130,7 +129,7 @@ export class WiredPinsSystem extends GameSystemWithFilter {
         for (let i = 0; i < pinsComp.slots.length; ++i) {
             const slot = pinsComp.slots[i];
             const worldPos = entity.components.StaticMapEntity.localTileToWorld(slot.pos);
-            const collidingEntity = this.root.map.getLayerContentXY(worldPos.x, worldPos.y, enumLayer.wires);
+            const collidingEntity = this.root.map.getLayerContentXY(worldPos.x, worldPos.y, "wires");
             if (collidingEntity) {
                 assertAlways(
                     collidingEntity.components.StaticMapEntity.getMetaBuilding().getIsReplaceable(),
diff --git a/src/js/globals.d.ts b/src/js/globals.d.ts
index 3f842e7e..51e4a2c3 100644
--- a/src/js/globals.d.ts
+++ b/src/js/globals.d.ts
@@ -193,6 +193,9 @@ declare interface TypedSignal<T extends Array<any>> {
     removeAll();
 }
 
+declare type Layer = "regular" | "wires";
+declare type ItemType = "shape" | "color" | "boolean";
+
 declare module "worker-loader?inline=true&fallback=false!*" {
     class WebpackWorker extends Worker {
         constructor();
diff --git a/src/js/savegame/serialization_data_types.js b/src/js/savegame/serialization_data_types.js
index 033acda1..9fb53bb8 100644
--- a/src/js/savegame/serialization_data_types.js
+++ b/src/js/savegame/serialization_data_types.js
@@ -456,7 +456,7 @@ export class TypeEnum extends BaseDataType {
      */
     constructor(enumeration = {}) {
         super();
-        this.availableValues = Object.keys(enumeration);
+        this.availableValues = Object.values(enumeration);
     }
 
     serialize(value) {