/**** 
* Classes
****/ 
// Define the 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 = 2;
	self.update = function () {
		self.y -= self.speed;
	};
});
// The assets will be automatically created and loaded by the LK engine
// Define the 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 () {
		self.x += self.speed;
		if (self.x < 0) {
			self.x = 0;
		} else if (self.x > 480) {
			self.x = 480;
		}
	};
});

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

/**** 
* Game Code
****/ 
// Initialize score text for car counter
var carCounterTxt = new Text2('Cars: 0', {
	size: 100,
	fill: "#ffffff"
});
carCounterTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(carCounterTxt);
var player = game.addChild(new Player());
player.x = 2048 / 2;
player.y = 2732 - 200;
var cars = [];
// Initialize 1 to 3 cars on the screen at a time
var initialCarCount = Math.floor(Math.random() * 3) + 1;
for (var i = 0; i < initialCarCount; i++) {
	var car = game.addChild(new Car());
	car.x = Math.random() * 2048;
	car.y = Math.random() * 2732;
	cars.push(car);
}
// Game update function
game.update = function () {
	// Update player and cars
	player.update();
	for (var i = 0; i < cars.length; i++) {
		cars[i].update();
	}
	// Check for collisions
	for (var i = 0; i < cars.length; i++) {
		if (player.intersects(cars[i])) {
			LK.showGameOver();
			break;
		}
	}
	// Check for off-screen cars
	for (var i = cars.length - 1; i >= 0; i--) {
		if (cars[i].y < 0) {
			cars[i].destroy();
			cars.splice(i, 1);
			var car = game.addChild(new Car());
			car.x = Math.random() * 2048;
			car.y = 0;
			cars.push(car);
		}
		carCounterTxt.setText('Cars: ' + cars.length);
	}
};
// Keyboard event listeners for controlling the player car
document.addEventListener('keydown', function (event) {
	if (event.key === 'ArrowLeft') {
		player.speed = -5;
	} else if (event.key === 'ArrowRight') {
		player.speed = 5;
	}
});
document.addEventListener('keyup', function (event) {
	if (event.key === 'ArrowLeft' || event.key === 'ArrowRight') {
		player.speed = 0;
	}
});

===================================================================
--- original.js
+++ change.js
@@ -87,15 +87,17 @@
 		}
 		carCounterTxt.setText('Cars: ' + cars.length);
 	}
 };
-// Game touch events
-game.down = function (x, y, obj) {
-	if (x < player.x) {
+// Keyboard event listeners for controlling the player car
+document.addEventListener('keydown', function (event) {
+	if (event.key === 'ArrowLeft') {
 		player.speed = -5;
-	} else {
+	} else if (event.key === 'ArrowRight') {
 		player.speed = 5;
 	}
-};
-game.up = function (x, y, obj) {
-	player.speed = 0;
-};
\ No newline at end of file
+});
+document.addEventListener('keyup', function (event) {
+	if (event.key === 'ArrowLeft' || event.key === 'ArrowRight') {
+		player.speed = 0;
+	}
+});
\ No newline at end of file