A slap in the brain - Antichamber

I have finally got my hands on Antichamber and I gotta say it is pretty amazing. In principle the game looks like your average first-person puzzle-platform game, maybe sort of like Portal, only with weird graphics. Once you start playing though you realize you are in for a crazy trip.

The game basically consists of a series of puzzles which you must solve to reach the exit. What makes the whole experience interesting is that it will often kick you into a state of surprise, most of the time because you (sensibly) expect the mechanics of the game to follow some real world logic and they usually don't.

If you have always wanted to know what it feels like to mess with psychedelic drugs but are too much of a wuss to actually do it, I'd wager Antichamber is about as close you can get to it.