Tech demo for a student project, but something I would love to see developed into a game, more-so if it retains the music, which I found quite immersive, actually.
[youtube]HOfll06X16c[/youtube]
You can download the demo here:
http://www.andrew.cmu.edu/user/abshih/MoSTDemo.zip
Very similar to Perspective, another game that uses perception to solve it's puzzles.