/**** 
* Classes
****/ 
// Bomb class
var Bomb = Container.expand(function () {
	var self = Container.call(this);
	var bombGraphics = self.attachAsset('bomb', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.explode = function () {
		// Create explosion effect
		var explosion = new Explosion();
		explosion.x = self.x;
		explosion.y = self.y;
		game.addChild(explosion);
		explosion.init();
		// Flash the screen
		LK.effects.flashScreen(0xff0000, 500);
		// Damage nearby buildings
		for (var i = 0; i < buildings.length; i++) {
			if (self.intersects(buildings[i])) {
				buildings[i].takeDamage(50);
			}
		}
		self.destroy();
	};
});
//<Assets used in the game will automatically appear here>
// Building class
var Building = Container.expand(function () {
	var self = Container.call(this);
	var buildingGraphics = self.attachAsset('building', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Create reconstruction animation
	var reconstruction = new BuildingReconstruction();
	reconstruction.x = self.x;
	reconstruction.y = self.y;
	game.addChild(reconstruction);
	reconstruction.init();
	self.health = 100;
	self.update = function () {
		if (self.health <= 0) {
			self.destroy();
		}
	};
	self.takeDamage = function (damage) {
		self.health -= damage;
	};
});
// BuildingReconstruction class
var BuildingReconstruction = Container.expand(function () {
	var self = Container.call(this);
	self.init = function () {
		// Create reconstruction effect
		LK.effects.flashObject(self, 0x00ff00, 500);
	};
});
// Car class
var Car = Container.expand(function () {
	var self = Container.call(this);
	var carGraphics = self.attachAsset('car', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 5;
	self.update = function () {
		self.x += self.speed;
		if (self.x > 2048) {
			self.x = -100;
		}
	};
});
// Explosion class
var Explosion = Container.expand(function () {
	var self = Container.call(this);
	self.init = function () {
		// Create explosion effect
		LK.effects.flashObject(self, 0xff0000, 500);
	};
});

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

/**** 
* Game Code
****/ 
// Initialize cars array
var cars = [];
// Create road
var road = new Graphics();
road.beginFill(0x808080);
road.drawRect(0, 1366 - 100, 2048, 100);
road.endFill();
game.addChild(road);
// Create cars
for (var i = 0; i < 5; i++) {
	var car = new Car();
	car.x = 400 * i;
	car.y = 1366 - 75;
	cars.push(car);
	game.addChild(car);
}
// Initialize bombs array
var bombs = [];
// Handle touch down event to place bombs
game.down = function (x, y, obj) {
	var bomb = new Bomb();
	bomb.x = x;
	bomb.y = y;
	bombs.push(bomb);
	game.addChild(bomb);
	LK.setTimeout(function () {
		bomb.explode();
	}, 1000);
};
// Update game state
game.update = function () {
	for (var i = 0; i < cars.length; i++) {
		cars[i].update();
	}
	for (var j = bombs.length - 1; j >= 0; j--) {
		if (bombs[j].destroyed) {
			bombs.splice(j, 1);
		}
	}
	// Add new buildings when all are destroyed
	if (buildings.length === 0) {
		LK.setTimeout(function () {
			for (var i = 0; i < 5; i++) {
				var building = new Building();
				building.x = 400 * (i + 1);
				building.y = 1366;
				buildings.push(building);
				game.addChild(building);
			}
		}, 1000);
	}
};

===================================================================
--- original.js
+++ change.js
@@ -57,8 +57,23 @@
 		// Create reconstruction effect
 		LK.effects.flashObject(self, 0x00ff00, 500);
 	};
 });
+// Car class
+var Car = Container.expand(function () {
+	var self = Container.call(this);
+	var carGraphics = self.attachAsset('car', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 5;
+	self.update = function () {
+		self.x += self.speed;
+		if (self.x > 2048) {
+			self.x = -100;
+		}
+	};
+});
 // Explosion class
 var Explosion = Container.expand(function () {
 	var self = Container.call(this);
 	self.init = function () {
@@ -76,17 +91,23 @@
 
 /**** 
 * Game Code
 ****/ 
-// Initialize buildings array
-var buildings = [];
-// Create buildings
+// Initialize cars array
+var cars = [];
+// Create road
+var road = new Graphics();
+road.beginFill(0x808080);
+road.drawRect(0, 1366 - 100, 2048, 100);
+road.endFill();
+game.addChild(road);
+// Create cars
 for (var i = 0; i < 5; i++) {
-	var building = new Building();
-	building.x = 400 * (i + 1);
-	building.y = 1366;
-	buildings.push(building);
-	game.addChild(building);
+	var car = new Car();
+	car.x = 400 * i;
+	car.y = 1366 - 75;
+	cars.push(car);
+	game.addChild(car);
 }
 // Initialize bombs array
 var bombs = [];
 // Handle touch down event to place bombs
@@ -101,13 +122,10 @@
 	}, 1000);
 };
 // Update game state
 game.update = function () {
-	for (var i = buildings.length - 1; i >= 0; i--) {
-		buildings[i].update();
-		if (buildings[i].health <= 0) {
-			buildings.splice(i, 1);
-		}
+	for (var i = 0; i < cars.length; i++) {
+		cars[i].update();
 	}
 	for (var j = bombs.length - 1; j >= 0; j--) {
 		if (bombs[j].destroyed) {
 			bombs.splice(j, 1);