http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=295247279&mt=8 I bought this last night and I can't stop playing it. It's a unique concept for a game. The geometry it uses seems pretty accurate (though the dev claims it's not mathematically perfect). The laser even has to move through prisms, which can throw a wrench in what you would assume to be an easy solution. Some of the puzzles are bit easy and the solution can found by accident, but a lot of them are really hard. There're 500 "mazes" right now. I would definitely recommend it.