var Paddle = Container.expand(function () {
	var self = Container.call(this);
	var paddleGraphics = self.createAsset('paddle', 'Paddle Graphics', 0.5, 0.5);
	self.speed = 10;
});
var Ball = Container.expand(function () {
	var self = Container.call(this);
	var ballGraphics = self.createAsset('ball', 'Ball Graphics', 0.5, 0.5);
	self.speed = {
		x: 5,
		y: 5
	};
	self.move = function () {
		self.x += self.speed.x;
		self.y += self.speed.y;
	};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var playerPaddle = self.addChild(new Paddle());
	var aiPaddle = self.addChild(new Paddle());
	var ball = self.addChild(new Ball());
	var paddles = [playerPaddle, aiPaddle];
	var score = {
		player: 0,
		ai: 0
	};
	playerPaddle.x = 100;
	playerPaddle.y = 2732 / 2;
	aiPaddle.x = 2048 - 100;
	aiPaddle.y = 2732 / 2;
	ball.x = 2048 / 2;
	ball.y = 2732 / 2;
	var scoreTxt = new Text2('0 - 0', {
		size: 150,
		fill: "#ffffff"
	});
	scoreTxt.anchor.set(.5, 0);
	LK.gui.topCenter.addChild(scoreTxt);
	var moveDirection = 0;
	LK.on('tick', function () {
		ball.move();
		stage.on('move', function (obj) {
			var event = obj.event;
			var pos = event.getLocalPosition(self);
			playerPaddle.y = pos.y - playerPaddle.height / 2;
		});
		aiPaddle.y = ball.y - aiPaddle.height / 2;
		for (var i = 0; i < paddles.length; i++) {
			if (ball.intersects(paddles[i])) {
				ball.speed.x *= -1;
			}
		}
		if (ball.y <= 0 || ball.y >= 2732) {
			ball.speed.y *= -1;
		}
		if (ball.x <= 0) {
			score.ai += 1;
			resetBall();
		}
		if (ball.x >= 2048) {
			score.player += 1;
			resetBall();
		}
		scoreTxt.setText(score.player + ' - ' + score.ai);
	});
	function resetBall() {
		ball.x = 2048 / 2;
		ball.y = 2732 / 2;
		ball.speed = {
			x: 5,
			y: 5
		};
	}
});

===================================================================
--- original.js
+++ change.js
@@ -1,11 +1,8 @@
 var Paddle = Container.expand(function () {
 	var self = Container.call(this);
 	var paddleGraphics = self.createAsset('paddle', 'Paddle Graphics', 0.5, 0.5);
 	self.speed = 10;
-	self.move = function () {
-		self.y += self.speed;
-	};
 });
 var Ball = Container.expand(function () {
 	var self = Container.call(this);
 	var ballGraphics = self.createAsset('ball', 'Ball Graphics', 0.5, 0.5);
@@ -42,10 +39,14 @@
 	LK.gui.topCenter.addChild(scoreTxt);
 	var moveDirection = 0;
 	LK.on('tick', function () {
 		ball.move();
-		playerPaddle.move();
-		aiPaddle.y = ball.y;
+		stage.on('move', function (obj) {
+			var event = obj.event;
+			var pos = event.getLocalPosition(self);
+			playerPaddle.y = pos.y - playerPaddle.height / 2;
+		});
+		aiPaddle.y = ball.y - aiPaddle.height / 2;
 		for (var i = 0; i < paddles.length; i++) {
 			if (ball.intersects(paddles[i])) {
 				ball.speed.x *= -1;
 			}