var AI = function () {
	this.makeMove = function (board) {
		var validMoves = [];
		for (var x = 0; x < 8; x++) {
			for (var y = 0; y < 8; y++) {
				if (board[x][y].state === 'empty' && board[x][y].isValidMove(x, y, 'white', board)) {
					validMoves.push({
						x: x,
						y: y
					});
				}
			}
		}
		if (validMoves.length > 0) {
			var move = validMoves[Math.floor(Math.random() * validMoves.length)];
			board[move.x][move.y].flip('white');
			playerTurn = 'black';
		}
	};
};
var Tile = Container.expand(function () {
	var self = Container.call(this);
	var tileGraphics = self.createAsset('tile', 'Game Tile', .5, .5);
	self.state = 'empty';
	self.isValidMove = function (x, y, player, board) {
		var opponent = player === 'black' ? 'white' : 'black';
		var directions = [{
			x: -1,
			y: 0
		}, {
			x: 1,
			y: 0
		}, {
			x: 0,
			y: -1
		}, {
			x: 0,
			y: 1
		}, {
			x: -1,
			y: -1
		}, {
			x: 1,
			y: 1
		}, {
			x: -1,
			y: 1
		}, {
			x: 1,
			y: -1
		}];
		for (var i = 0; i < directions.length; i++) {
			var dir = directions[i];
			var j = 1;
			var tilesToFlip = [];
			while (true) {
				var checkX = x + dir.x * j;
				var checkY = y + dir.y * j;
				if (checkX < 0 || checkX >= 8 || checkY < 0 || checkY >= 8) break;
				var checkTile = board[checkX][checkY];
				if (checkTile.state === 'empty') break;
				if (checkTile.state === opponent) {
					tilesToFlip.push(checkTile);
				} else if (checkTile.state === player) {
					if (tilesToFlip.length > 0) {
						return tilesToFlip;
					}
					break;
				}
				j++;
			}
		}
		return false;
	};
	self.flip = function (newState) {
		self.state = newState;
		if (self.state === 'black') {
			self.createAsset('blackTile', 'Black Tile', .5, .5);
		} else if (self.state === 'white') {
			self.createAsset('whiteTile', 'White Tile', .5, .5);
		}
	};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var board = [];
	var ai = new AI();
	var playerTurn = 'black';
	var tile = new Tile();
	var boardWidth = 8 * tile.width;
	var boardHeight = 8 * tile.height;
	var boardStartX = (2048 - boardWidth) / 2;
	var boardStartY = (2732 - boardHeight) / 2;
	for (var i = 0; i < 8; i++) {
		board[i] = [];
		for (var j = 0; j < 8; j++) {
			var tile = self.addChild(new Tile());
			tile.x = boardStartX + i * tile.width;
			tile.y = boardStartY + j * tile.height;
			board[i][j] = tile;
			tile.on('down', (function (tile, i, j) {
				return function (obj) {
					if (playerTurn === 'black' && tile.state === 'empty') {
						var tilesToFlip = tile.isValidMove(i, j, playerTurn, board);
						if (tilesToFlip) {
							tile.flip('black');
							for (var k = 0; k < tilesToFlip.length; k++) {
								tilesToFlip[k].flip('black');
							}
							playerTurn = 'white';
							if (playerTurn === 'white') {
								ai.makeMove(board);
								playerTurn = 'black';
							}
						}
					}
				};
			})(tile, i, j));
		}
	}
	board[3][3].flip('white');
	board[3][4].flip('black');
	board[4][3].flip('black');
	board[4][4].flip('white');
	LK.on('tick', function () {});
});

===================================================================
--- original.js
+++ change.js
@@ -71,18 +71,14 @@
 			}
 		}
 		return false;
 	};
-	self.flip = function (newState, tilesToFlip) {
-		if (tilesToFlip && tilesToFlip.length > 0) {
-			for (var i = 0; i < tilesToFlip.length; i++) {
-				tilesToFlip[i].state = newState;
-				if (newState === 'black') {
-					tilesToFlip[i].createAsset('blackTile', 'Black Tile', .5, .5);
-				} else if (newState === 'white') {
-					tilesToFlip[i].createAsset('whiteTile', 'White Tile', .5, .5);
-				}
-			}
+	self.flip = function (newState) {
+		self.state = newState;
+		if (self.state === 'black') {
+			self.createAsset('blackTile', 'Black Tile', .5, .5);
+		} else if (self.state === 'white') {
+			self.createAsset('whiteTile', 'White Tile', .5, .5);
 		}
 	};
 });
 var Game = Container.expand(function () {
@@ -104,11 +100,14 @@
 			board[i][j] = tile;
 			tile.on('down', (function (tile, i, j) {
 				return function (obj) {
 					if (playerTurn === 'black' && tile.state === 'empty') {
-						var validTilesToFlip = tile.isValidMove(i, j, playerTurn, board);
-						if (validTilesToFlip) {
-							tile.flip('black', validTilesToFlip);
+						var tilesToFlip = tile.isValidMove(i, j, playerTurn, board);
+						if (tilesToFlip) {
+							tile.flip('black');
+							for (var k = 0; k < tilesToFlip.length; k++) {
+								tilesToFlip[k].flip('black');
+							}
 							playerTurn = 'white';
 							if (playerTurn === 'white') {
 								ai.makeMove(board);
 								playerTurn = 'black';