/**** 
* Classes
****/ 
// Define a Bullet class
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -10;
	self.update = function () {
		self.y += self.speed;
		if (self.y < -bulletGraphics.height) {
			self.destroy();
		}
	};
});
// Define a Hero class
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroGraphics = self.attachAsset('hero', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.shoot = function () {
		var bullet = new Bullet();
		bullet.x = self.x;
		bullet.y = self.y - heroGraphics.height / 2;
		bullets.push(bullet);
		game.addChild(bullet);
	};
	self.move = function (x, y) {
		self.x = x;
		self.y = y;
	};
});
// Define a SpaceShip class
var SpaceShip = Container.expand(function () {
	var self = Container.call(this);
	var shipGraphics = self.attachAsset('hero', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.shoot = function () {
		var bullet = new Bullet();
		bullet.x = self.x;
		bullet.y = self.y - shipGraphics.height / 2;
		bullets.push(bullet);
		game.addChild(bullet);
	};
	self.move = function (x, y) {
		self.x = x;
		self.y = y;
	};
});
// Assets will be automatically created and loaded by the LK engine based on their usage in the code.
// Define a Zombie class
var Zombie = Container.expand(function () {
	var self = Container.call(this);
	this.level = 1; // Initialize level property
	var zombieGraphics = self.attachAsset('zombie', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 2;
	self.update = function () {
		self.y += self.speed;
		self.x += Math.sin(self.y / 100) * 5; // Add horizontal movement
		if (self.y > 2732) {
			self.respawn();
			self.level++;
			self.speed += 0.5; // Increase speed with level
			LK.setScore(LK.getScore() - 1);
			scoreTxt.setText('Score: ' + LK.getScore());
		}
		if (self.intersects(hero)) {
			self.attack();
		}
	};
	self.attack = function () {
		LK.effects.flashObject(hero, 0xff0000, 500);
	};
	self.respawn = function () {
		self.y = -zombieGraphics.height;
		self.x = Math.random() * 2048;
	};
});

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

/**** 
* Game Code
****/ 
// Initialize score display
var scoreTxt = new Text2('Score: 0', {
	size: 100,
	fill: "#ffffff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Initialize game variables
var hero = new Hero();
hero.x = 2048 / 2;
hero.y = 2732 - 150;
game.addChild(hero);
var spaceShip = new SpaceShip();
spaceShip.x = 2048 / 2;
spaceShip.y = 2732 - 150;
game.addChild(spaceShip);
var zombies = [];
for (var i = 0; i < 5; i++) {
	var zombie = new Zombie();
	zombie.x = Math.random() * 2048;
	zombie.y = Math.random() * 2732;
	zombies.push(zombie);
	game.addChild(zombie);
}
var bullets = [];
// Handle game updates
game.update = function () {
	for (var i = bullets.length - 1; i >= 0; i--) {
		bullets[i].update();
		for (var j = zombies.length - 1; j >= 0; j--) {
			if (bullets[i].intersects(zombies[j])) {
				bullets[i].destroy();
				bullets.splice(i, 1);
				zombies[j].respawn();
				LK.setScore(LK.getScore() + 1);
				scoreTxt.setText('Score: ' + LK.getScore());
				break;
			}
		}
	}
	if (LK.ticks % Math.max(600 - zombies[0].level * 10, 300) === 0) {
		// Increase level every 10 seconds (assuming 60 FPS)
		for (var l = 0; l < zombies.length; l++) {
			zombies[l].level++;
			zombies[l].speed += 0.5; // Increase speed with level
		}
	}
	if (LK.ticks % 1800 === 0) {
		// Every 30 seconds
		var newZombie = new Zombie();
		newZombie.x = Math.random() * 2048;
		newZombie.y = -newZombie.height;
		zombies.push(newZombie);
		game.addChild(newZombie);
	}
	for (var k = 0; k < zombies.length; k++) {
		zombies[k].update();
		if (zombies[k].intersects(hero)) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
	}
};
// Handle touch events for moving the hero
game.down = function (x, y, obj) {
	hero.move(x, y);
	hero.shoot();
};

===================================================================
--- original.js
+++ change.js
@@ -18,9 +18,9 @@
 });
 // Define a Hero class
 var Hero = Container.expand(function () {
 	var self = Container.call(this);
-	var heroGraphics = self.attachAsset('hero3D', {
+	var heroGraphics = self.attachAsset('hero', {
 		anchorX: 0.5,
 		anchorY: 0.5
 	});
 	self.shoot = function () {