Last weekend I tried out Braid
, an unusual platform puzzle game created by an indy developer. First, it seems like a Super Mario Bros clone with a nice art style (and I thought: "why on earth are all people saying this game is sooo great!? It's a ****ing jump'n'run!?"), but after the first few levels, or when you died the first time, you'll notice that Braid is very different: It's all about time manipulation and solving brain hurting puzzles which is very entertaining. Also, the music in the game is absolutely nice.
You can download the braid demo for example from Greenhouse