I don't know if anyone's played this, but it's essentially a Portal clone...but a really good one (and no, no portals involved).
It's a First Person Puzzle-Platformer (yay, capitalization) broken into rough rooms like Portal. The catch is that instead of using portals, you have a mechanism to change "dimensions". There's a heavy dimension, a soft dimension, a slow dimension, and another that I totally can't remember right now. Each is mapped to a button and switching into that dimension changes the physical properties and mechanics of the room around you until you switch out.
So, you may need to switch to the soft dimension to grab a safe you wouldn't otherwise be able to pick up, throw it, switch the slow dimension on, jump over a river of floating couches (what?) catch it, throw it again but in a different direction, and turn it heavy so that it can become more dense and pass through a laser wall.
I've actually been having a ton of fun with it, and can't really agree with the main complaint against the game - too many platform puzzles - but that may be because I'm playing on a gamepad and the jumps really aren't that hard. Anyways, if you can grab it on sale it's a pretty good time killer.