Trism is a puzzle game designed around the iPhone's ability to touch the screen and tilt it. The screen is filled with a board of triangles (or 'Trisms'), and the player can clear away Trisms by making three or more of the same color touch. These Trisms then disappear, and more slide on-screen. The direction that the new Trisms slide in from is determined by the position that the player holds the iPhone. A skilled player can use varying directions to their advantage, allowing for combos of multiple Trisms being cleared.
To complicate matters, Trisms occasionally get 'screwed in', meaning that all the Trisms on that row can no longer be moved, and instead must be cleared to restore the row back to normal. Other Trisms may become bombs with timers on them - if the player doesn't clear these dangerous Trisms before the timer runs out, the bomb explodes and it's Game Over!
Trism has three different modes of play:
Infinism - play for as long as you can! There's no time limit here, it's just the bombs that can end your game.
Terminism - a timed game - keep clearing those Trisms to stay in the game!
Syllogism - a puzzle mode where you have a set amount of moves to clear all the Trisms in play.