/**** 
* Classes
****/
// Paddle class for player
var PlayerPaddle = Container.expand(function () {
	var self = Container.call(this);
	var paddleGraphics = self.createAsset('paddle', 'Player Paddle Graphics', 0.5, 0.5);
	self.speed = 10;
	self.moveUp = function () {
		if (self.y > 0) {
			self.y -= self.speed;
		}
	};
	self.moveDown = function () {
		if (self.y < game.height - paddleGraphics.height) {
			self.y += self.speed;
		}
	};
});
// Paddle class for AI
var AIPaddle = Container.expand(function () {
	var self = Container.call(this);
	var paddleGraphics = self.createAsset('ai_paddle', 'AI Paddle Graphics', 0.5, 0.5);
	self.speed = 10;
	self.moveUp = function () {
		if (self.y > 0) {
			self.y -= self.speed;
		}
	};
	self.moveDown = function () {
		if (self.y < game.height - paddleGraphics.height) {
			self.y += self.speed;
		}
	};
});
// Ball class
var Ball = Container.expand(function () {
	var self = Container.call(this);
	var ballGraphics = self.createAsset('ball', 'Ball Graphics', 0.5, 0.5);
	self.velocity = {
		x: 5,
		y: 5
	};
	self.move = function () {
		self.x += self.velocity.x;
		self.y += self.velocity.y;
	};
	self.reset = function () {
		self.x = game.width / 2;
		self.y = game.height / 2;
		self.velocity = {
			x: 5,
			y: 5
		};
	};
	self.bounce = function (axis) {
		if (axis === 'x') {
			self.velocity.x *= -1;
			LK.Audio.play('hit_paddle_sound');
		} else if (axis === 'y') {
			self.velocity.y *= -1;
		}
	};
});
// Background class
var Background = Container.expand(function () {
	var self = Container.call(this);
	var backgroundGraphics = self.createAsset('background', 'Background Graphics', 0.5, 0.5);
	// Set background size to cover the entire game area
	backgroundGraphics.width = game.width;
	backgroundGraphics.height = game.height;
});

/**** 
* Initialize Game
****/
// Initialize and add background to the game
var game = new LK.Game({
	backgroundColor: 0x000000 // Init game with black background
});

/**** 
* Game Code
****/
// Initialize and add background to the game
var background = game.addChild(new Background());
background.x = game.width / 2;
background.y = game.height / 2;
// Play background music
if (LK.Audio.isLoaded('background_music')) {
	LK.Audio.play('background_music', {
		loop: true
	});
}
// Initialize paddles and ball
var playerPaddle = new PlayerPaddle();
var aiPaddle = new AIPaddle();
var ball = new Ball();
// Set initial positions
playerPaddle.x = 100;
playerPaddle.y = game.height / 2;
aiPaddle.x = game.width - 100;
aiPaddle.y = game.height / 2;
ball.reset();
// Add paddles and ball to the game
game.addChild(playerPaddle);
game.addChild(aiPaddle);
game.addChild(ball);
// AI logic
function aiMove() {
	if (ball.y < aiPaddle.y) {
		aiPaddle.moveUp();
	} else if (ball.y > aiPaddle.y) {
		aiPaddle.moveDown();
	}
}
// Game tick event
LK.on('tick', function () {
	// Mouse follow behavior for player paddle
	game.on('move', function (obj) {
		var mousePos = obj.event.getLocalPosition(game);
		playerPaddle.y = mousePos.y - playerPaddle.height / 2;
		// Keep paddle within game bounds
		if (playerPaddle.y < 0) {
			playerPaddle.y = 0;
		}
		if (playerPaddle.y > game.height - playerPaddle.height) {
			playerPaddle.y = game.height - playerPaddle.height;
		}
	});
	// Move ball
	ball.move();
	// Ball collision with top and bottom
	if (ball.y <= 0 || ball.y >= game.height) {
		ball.bounce('y');
	}
	// Ball collision with paddles
	if (ball.intersects(playerPaddle) || ball.intersects(aiPaddle)) {
		ball.bounce('x');
	}
	// Ball out of bounds
	if (ball.x <= 0 || ball.x >= game.width) {
		ball.reset();
	}
	// AI movement
	aiMove();
});

===================================================================
--- original.js
+++ change.js
@@ -86,11 +86,13 @@
 var background = game.addChild(new Background());
 background.x = game.width / 2;
 background.y = game.height / 2;
 // Play background music
-LK.Audio.play('background_music', {
-	loop: true
-});
+if (LK.Audio.isLoaded('background_music')) {
+	LK.Audio.play('background_music', {
+		loop: true
+	});
+}
 // Initialize paddles and ball
 var playerPaddle = new PlayerPaddle();
 var aiPaddle = new AIPaddle();
 var ball = new Ball();