Braid (video game - Wikipedia, the free encyclopedia)
If you thought Portal was a mind****, you're in for a rollercoaster ride.
You have to manipulate time in order to make yourself and puzzles move forward and backwards. There are also objects that are persistent and unaffected by your time manipulation; So you may need to go somewhere, run over to and hit a switch, platform starts moving, then rewind time so you return to your initial position and the platform arrives.
Definitely my best purchase on Live so far. Get ready to use your brain.
Gametrailers.com - Braid - Cloud Bridge Gameplay
Yeah, it has been getting a lot of hype.
Braid (xbox360: 2008): Reviews
This and Geometry Wars 2 on consecutive weeks.
Plus Pixel Junk Eden on PS3. Too many games.... too little time.