/**** 
* Classes
****/ 
// 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 = 3;
	self.update = function () {
		self.y += self.speed;
		if (self.y > 2732) {
			self.destroy();
		}
	};
});
// EnemyBullet class
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 10;
	self.update = function () {
		self.y += self.speed;
		if (self.y > 2732) {
			self.destroy();
		}
	};
});
// Hero rocket launcher
var HeroBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('heroBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -10;
	self.update = function () {
		self.y += self.speed;
		if (self.y < 0) {
			self.destroy();
		}
	};
});
//<Assets used in the game will automatically appear here>
// Tank class
var Tank = Container.expand(function () {
	var self = Container.call(this);
	var tankGraphics = self.attachAsset('tank', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 5;
	self.update = function () {
		// Update logic for tank
	};
	self.shoot = function () {
		var bullet = new HeroBullet();
		bullet.x = self.x;
		bullet.y = self.y;
		game.addChild(bullet);
		heroBullets.push(bullet);
	};
});

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

/**** 
* Game Code
****/ 
// Initialize arrays and variables
var heroBullets = [];
var enemyBullets = [];
var enemies = [];
var score = 0;
// Create tank instance
var tank = new Tank();
tank.x = 2048 / 2;
tank.y = 2732 - 200;
game.addChild(tank);
// Create score text
var scoreTxt = new Text2('0', {
	size: 150,
	fill: "#ffffff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Handle game updates
game.update = function () {
	// Update tank
	tank.update();
	// Update hero bullets
	for (var i = heroBullets.length - 1; i >= 0; i--) {
		heroBullets[i].update();
		if (heroBullets[i].intersects(enemies)) {
			heroBullets[i].destroy();
			heroBullets.splice(i, 1);
			score += 10;
			scoreTxt.setText(score);
		}
	}
	// Update enemy bullets
	for (var j = enemyBullets.length - 1; j >= 0; j--) {
		enemyBullets[j].update();
		if (enemyBullets[j].intersects(tank)) {
			enemyBullets[j].destroy();
			enemyBullets.splice(j, 1);
			LK.showGameOver();
		}
	}
	// Update enemies
	for (var k = enemies.length - 1; k >= 0; k--) {
		enemies[k].update();
		if (enemies[k].intersects(tank)) {
			enemies[k].destroy();
			enemies.splice(k, 1);
			LK.showGameOver();
		}
	}
	// Spawn new enemies
	if (LK.ticks % 60 == 0) {
		var enemy = new Enemy();
		enemy.x = Math.random() * 2048;
		enemy.y = 0;
		game.addChild(enemy);
		enemies.push(enemy);
	}
};
// Handle touch events
game.down = function (x, y, obj) {
	tank.shoot();
};
game.move = function (x, y, obj) {
	tank.x = x;
	tank.y = y;
};
game.up = function (x, y, obj) {};

===================================================================
--- original.js
+++ change.js
@@ -142,7 +142,5 @@
 game.move = function (x, y, obj) {
 	tank.x = x;
 	tank.y = y;
 };
-game.up = function (x, y, obj) {
-	// No action needed on touch up
-};
\ No newline at end of file
+game.up = function (x, y, obj) {};
\ No newline at end of file