iPhone puzzler slides shapes along a triangle's three sides.

Trism bends a weary match-three puzzle genre by adding another axis. Instead of sliding up or down on a square grid like most other games, you’ll move triangles along their three sides. On top of that, the game senses the angle of the iPhone, sliding in new pieces depending on your orientation of down. That motion awareness makes Trism unique, but it can also frustrate.

After making a match, you’ll have a brief moment to reorient the phone so the initial gap gets filled from a certain direction. And you’ll usually create a semi-permanent gap after a match, since a triangle pointing down can’t slide against a triangle pointing up in the same row. A group of five-or-more creates a wildcard that when matched fills in all of those gaps.

Trism relies on accurate, quick sensing of the iPhone orientation, which often works but sometimes frustrates. We usually got pieces to snap in from the proper direction, but once in a while, we missed out on big chain reactions because the iPhone thought we were tilting a different way.