Developer: DePaul University seniors
Platforms: PC, Mac
Tessallation is described as a first person, single player co-op puzzle game. Now single player co-op seems like an oxymoron but that's exactly what Tessallation is. You use the power of time travel to work with your past selves. Single player co-op indeed.
To complete each level, you must learn to work with yourself. Complete one action, then rewind time. Your past self perform that "recorded" action, while you do something else. Work in tandem with countless clones as you synchronize button presses, manipulate weight-activated switches, play catch with yourself, and other paradox-breaking tasks.
Tessallation is short but that's good thing. There's no filler and difficulty ramps up fast. Stay in school, loop through time, and enjoy this abstract puzzle game without spending a cent. You can download Tessallation here.