Make final ending return explicit

src/game/scenes/EndingScene.ts

@@ -16,10 +16,8 @@ export class EndingScene extends Phaser.Scene {
   create() {
     this.ready = false;
     this.createFallbackTexture();
-    this.ensureBackgroundLoaded(() => {
-      this.ready = true;
-      this.drawEnding();
-    });
+    this.renderEnding();
+    this.ensureBackgroundLoaded(() => this.renderEnding());
   }
 
   getDebugState() {
@@ -49,14 +47,30 @@ export class EndingScene extends Phaser.Scene {
       return;
     }
 
-    this.load.once('complete', onReady);
+    let finished = false;
+    const finish = () => {
+      if (finished) {
+        return;
+      }
+      finished = true;
+      onReady();
+    };
+    this.load.once('complete', finish);
     this.load.once('loaderror', () => {
       console.warn(`Failed to load ending background ${this.backgroundKey}`);
+      finish();
     });
     this.load.image(this.backgroundKey, url);
     this.load.start();
   }
 
+  private renderEnding() {
+    this.tweens.killAll();
+    this.children.removeAll(true);
+    this.drawEnding();
+    this.ready = true;
+  }
+
   private createFallbackTexture() {
     if (this.textures.exists('ending-fallback')) {
       return;