Here are the rules:
Here's a Moonlight edition for anyone who wants to give it a try: http://games.usvsth3m.com/2048/moonlight-edition-4/HOW TO PLAY: Use your arrow keys to move the tiles.
When two identical tiles touch, they merge and become the next level of tile. Get a tile to the eleventh level to win.
ETA: Alternative link for folks who are having trouble with the first one: http://games.usvsth3m.com/2048/moonlight-edition-6/