Teamtris

Bored of the thousand Tetris-like games? Teamtris is pretty much different. You can play Tetris with two people at the same time, on the same computer. There are two ways to play this game against your opponent. The first way is to play in a different square, so you both got your own game. The player with the most lines wins. A second way to play the game in the same square.

The second option is fun, because you can make it you opponent very hard.