Created in 2010 by the fellows of StabYourself.net, creators of Mari0, and is now in its second incarnation, Not Tetris is ... well, not your average Tetris clone. Sure, it looks like Tetris, and it sounds like Tetris, but it also incorporates a full Physics Engine: Pieces can move and spin freely in a full 360 degrees, and if it lands at an angle it will tilt and fall over, making the pile difficult to stack in an orderly fashion, and even more difficult to clear a line — it's almost impossible to play like standard Tetris.
The game is available for free under an open-source license.
This game provides examples of the following:
- Anti-Frustration Features: Only 80% of a line needs to be filled for that line to be removed.
- Beyond the Impossible: The physics in the game make it possible to clear more than four lines at a time. It's also possible to drop a block in such a way that it clears a row that it doesn't even touch.
- Disaster Dominoes: The blocks that you've already placed are not fixed in place, and thus can be dislodged by a badly placed one. Woe betide the player if a stack topples over and makes it impossible to clear the bottom rows.
- Endless Game: Much like the original Tetris, Not Tetris 2's standard mode proceeds until the board is filled and the player loses. "Stack" mode prevents lines from being cleared, but scores the player on how many pieces they can stack before filling the board.
- Nintendo Hard: The addition of physics makes it much tougher to successfully clear lines in an organized manner when compared to the original game.