fix ts error

src/bird.ts

@@ -20,7 +20,7 @@ export class Bird extends ex.Actor {
     }
 
     // Step 3
-    override onInitialize(engine: ex.Engine): void {
+    override onInitialize(): void {
         // this.acc = ex.vec(0, 1500); // pixels per second per second
 
         // Step 6
@@ -39,7 +39,7 @@ export class Bird extends ex.Actor {
     }
 
     // Step 4
-    override onPostUpdate(engine: ex.Engine, elapsedMs: number): void {
+    override onPostUpdate(engine: ex.Engine): void {
         if (!this.playing) return;
 
         // if the space bar or the first pointer was down
@@ -78,7 +78,7 @@ export class Bird extends ex.Actor {
     }
 
     // Step 9
-    override onCollisionStart(self: ex.Collider, other: ex.Collider): void {
+    override onCollisionStart(_self: ex.Collider, other: ex.Collider): void {
         if (other.owner instanceof Pipe ||
             other.owner instanceof Ground
         ) {

src/ground.ts

@@ -21,7 +21,7 @@ export class Ground extends ex.Actor {
         this.graphics.use(this.groundSprite);
     }
 
-    onPostUpdate(engine: ex.Engine, elapsedMs: number): void {
+    onPostUpdate(_engine: ex.Engine, elapsedMs: number): void {
         if (!this.moving) return;
         this.groundSprite.sourceView.x += Config.PipeSpeed * (elapsedMs / 1000);
     }

src/pipe-factory.ts

@@ -11,7 +11,7 @@ export class PipeFactory {
     constructor(
         private level: Level,
         private random: ex.Random,
-        private intervalMs: number) {
+        intervalMs: number) {
             this.timer = new ex.Timer({
                 interval: intervalMs,
                 repeats: true,

src/pipe.ts

@@ -19,7 +19,7 @@ export class Pipe extends ex.Actor {
     }
 
     // Step 9.5
-    override onInitialize(engine: ex.Engine): void {
+    override onInitialize(): void {
         const pipeEnd = Resources.PipeImage.toSprite();
         // Stretch the pipe sprite
         // by default ImageSource use clamp which re-uses the border pixels