15-Puzzle Battle

Play 15-Puzzle against your friends. The advantage over common games is: It is not necessery that your opponent is online during the game. Just solve a puzzle and send your challenge. As soon as your opponent is online next time, he can see your request and solves the same puzzle. If your opponent has accept the challenge, the game is finished you can see the results in the category "New finished challenges". So keep an eye on it!