/**** 
* Classes
****/ 
var Snake = Container.expand(function () {
	var self = Container.call(this);
	self.body = [];
	self.direction = 'right';
	self.attachAsset('snakeBody', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.body.push(self);
	self.update = function () {
		var head = self.body[0];
		var newHead;
		switch (self.direction) {
			case 'right':
				newHead = {
					x: head.x + 1,
					y: head.y
				};
				break;
			case 'left':
				newHead = {
					x: head.x - 1,
					y: head.y
				};
				break;
			case 'up':
				newHead = {
					x: head.x,
					y: head.y - 1
				};
				break;
			case 'down':
				newHead = {
					x: head.x,
					y: head.y + 1
				};
				break;
		}
		self.body.unshift(newHead);
		self.body.pop();
	};
	self.changeDirection = function (newDirection) {
		var allowedDirections;
		switch (self.direction) {
			case 'right':
			case 'left':
				allowedDirections = ['up', 'down'];
				break;
			case 'up':
			case 'down':
				allowedDirections = ['right', 'left'];
				break;
		}
		if (allowedDirections.indexOf(newDirection) > -1) {
			self.direction = newDirection;
		}
	};
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000000,
	width: 2500
});

/**** 
* Game Code
****/ 
var snake = game.addChild(new Snake());
snake.x = 2048 / 2;
snake.y = 2732 / 2;
game.update = function () {
	snake.update();
};
game.down = function (x, y, obj) {
	var direction;
	switch (obj.key) {
		case 'ArrowUp':
			direction = 'up';
			break;
		case 'ArrowDown':
			direction = 'down';
			break;
		case 'ArrowLeft':
			direction = 'left';
			break;
		case 'ArrowRight':
			direction = 'right';
			break;
	}
	snake.changeDirection(direction);
};
;

===================================================================
--- original.js
+++ change.js
@@ -78,9 +78,9 @@
 	snake.update();
 };
 game.down = function (x, y, obj) {
 	var direction;
-	switch (obj.event.key) {
+	switch (obj.key) {
 		case 'ArrowUp':
 			direction = 'up';
 			break;
 		case 'ArrowDown':