If the Soviet Union did anything for the world, it was Tetris. Awful shame they had no copyright laws and it was knicked really.
When someone loses, and play stops, you can click the funny small icon on the right to begin play.
Left and right arrow keys move the shape left and right, your objective is to clear lines by filling them. Any squares above them will fall down.
A second player (or the first if playing solo) can take part in a co-op mode. Start clicking the Z coins to start playing player 2. When 10 coins have been collected, that player can delete a non-moving block to help the other player.
(Course, you can download and play by yourself)
Scores are saved locally, and now with v1.1 online with 3 medals to go for!
Zetris is now part of the "AceMedalTable" ! You can take part after gaining medals in this game by this link and following the instructions:
http://www.byond.com/games/Acebloke/AceMedalTable