/**** 
* Classes
****/
// Hero ship class
var HeroShip = Container.expand(function () {
	var self = Container.call(this);
	var shipGraphics = self.createAsset('heroShip', 'Cute smiley ship', 0.5, 0.5);
	self.speed = 5;
	self.moveLeft = function () {
		self.x -= self.speed;
	};
	self.moveRight = function () {
		self.x += self.speed;
	};
	self.shoot = function () {
		var bullet = new HeroBullet();
		bullet.x = self.x;
		bullet.y = self.y - self.height / 2;
		game.addChild(bullet);
		return bullet;
	};
	self.moveTo = function (targetX, targetY) {
		var distance = Math.sqrt(Math.pow(targetX - self.x, 2) + Math.pow(targetY - self.y, 2));
		var duration = distance / self.speed * 60; // Duration based on speed and 60FPS
		self.customTween(self, targetX, targetY, duration);
	};
});
// Hero bullet class
var HeroBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.createAsset('heroBullet', 'Heart bullet', 0.5, 1);
	self.speed = -10;
	self.move = function () {
		self.y += self.speed;
	};
});
// Enemy ship class
var EnemyShip = Container.expand(function () {
	var self = Container.call(this);
	var shipGraphics = self.createAsset('enemyShip', 'Evil smiley', 0.5, 0.5);
	self.speed = 2;
	self.move = function () {
		self.y += self.speed;
	};
});

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

/**** 
* Game Code
****/
// Touch controls for hero ship to move towards touch position
// Initialize important asset arrays
game.on('down', function (obj) {
	var touchPos = obj.event.getLocalPosition(game);
	heroShip.moveTo(touchPos.x, heroShip.y);
});
var heroBullets = [];
var enemyShips = [];

// Create hero ship
var heroShip = game.addChild(new HeroShip());
heroShip.x = game.width / 2;
heroShip.y = game.height - 150;

// Create enemies
function spawnEnemy() {
	var enemy = new EnemyShip();
	enemy.x = Math.random() * (game.width - enemy.width) + enemy.width / 2;
	enemy.y = -enemy.height / 2;
	enemyShips.push(enemy);
	game.addChild(enemy);
}

// Spawn initial enemies
for (var i = 0; i < 5; i++) {
	spawnEnemy();
}

// Game tick event
LK.on('tick', function () {
	// Move hero bullets
	for (var i = heroBullets.length - 1; i >= 0; i--) {
		var bullet = heroBullets[i];
		bullet.move();
		if (bullet.y < -bullet.height) {
			bullet.destroy();
			heroBullets.splice(i, 1);
		} else {
			// Check collision with enemies
			for (var j = enemyShips.length - 1; j >= 0; j--) {
				if (bullet.intersects(enemyShips[j])) {
					bullet.destroy();
					enemyShips[j].destroy();
					heroBullets.splice(i, 1);
					enemyShips.splice(j, 1);
					break;
				}
			}
		}
	}

	// Move enemy ships
	for (var i = enemyShips.length - 1; i >= 0; i--) {
		var enemy = enemyShips[i];
		enemy.move();
		if (enemy.y > game.height + enemy.height / 2) {
			enemy.destroy();
			enemyShips.splice(i, 1);
			spawnEnemy();
		}
	}

	// Shoot bullets
	if (LK.ticks % 30 == 0) {
		heroBullets.push(heroShip.shoot());
	}
});

===================================================================
--- original.js
+++ change.js
@@ -21,12 +21,9 @@
 	};
 	self.moveTo = function (targetX, targetY) {
 		var distance = Math.sqrt(Math.pow(targetX - self.x, 2) + Math.pow(targetY - self.y, 2));
 		var duration = distance / self.speed * 60; // Duration based on speed and 60FPS
-		LK.tween(self, {
-			x: targetX,
-			y: targetY
-		}, duration);
+		self.customTween(self, targetX, targetY, duration);
 	};
 });
 // Hero bullet class
 var HeroBullet = Container.expand(function () {