/**** 
* Classes
****/ 
// 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;
	};
});
// Enemy class
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var enemyGraphics = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 2;
	self.update = function () {
		// Enemy movement logic goes here
	};
});
// The assets will be automatically created and loaded by the LK engine
// Player class
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 5;
	self.update = function () {
		// Player movement logic goes here
	};
});

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

/**** 
* Game Code
****/ 
// Initialize player, bullets and enemies
var player = game.addChild(new Player());
player.x = 2048 / 2;
player.y = 2732 - 100;
var bullets = [];
var enemies = [];
// Game update function
game.update = function () {
	// Player movement logic
	game.move = function (x, y, obj) {
		if (x < player.x) {
			player.x -= player.speed;
		} else if (x > player.x) {
			player.x += player.speed;
		}
	};
	// Shooting logic
	game.down = function (x, y, obj) {
		var bullet = new Bullet();
		bullet.x = player.x;
		bullet.y = player.y;
		bullets.push(bullet);
		game.addChild(bullet);
	};
	// Enemy spawning logic
	if (LK.ticks % 120 == 0) {
		var enemy = new Enemy();
		enemy.x = Math.random() * 2048;
		enemy.y = 0;
		enemies.push(enemy);
		game.addChild(enemy);
	}
	// Bullet and enemy update logic
	for (var i = bullets.length - 1; i >= 0; i--) {
		if (bullets[i].y < 0) {
			bullets[i].destroy();
			bullets.splice(i, 1);
		}
	}
	for (var i = enemies.length - 1; i >= 0; i--) {
		if (enemies[i].y > 2732) {
			enemies[i].destroy();
			enemies.splice(i, 1);
		}
	}
	// Collision detection
	for (var i = bullets.length - 1; i >= 0; i--) {
		for (var j = enemies.length - 1; j >= 0; j--) {
			if (bullets[i].intersects(enemies[j])) {
				bullets[i].destroy();
				bullets.splice(i, 1);
				enemies[j].destroy();
				enemies.splice(j, 1);
				break;
			}
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -65,15 +65,15 @@
 			player.x += player.speed;
 		}
 	};
 	// Shooting logic
-	if (LK.keys['Space']) {
+	game.down = function (x, y, obj) {
 		var bullet = new Bullet();
 		bullet.x = player.x;
 		bullet.y = player.y;
 		bullets.push(bullet);
 		game.addChild(bullet);
-	}
+	};
 	// Enemy spawning logic
 	if (LK.ticks % 120 == 0) {
 		var enemy = new Enemy();
 		enemy.x = Math.random() * 2048;