To the people who haven't played Playdead's Limbo yet: do it! Further expanding your options, the puzzle-platformer can now be played on iPhone 4S, iPad 2, and fifth-gen iPod touch or newer devices. From what I've heard, it's not the ideal way to play, but the $4.99 price point helps.
This new App Store release comes in addition to versions of the game on Windows, Mac, PlayStation 3, Xbox 360, and PlayStation Vita. So, yeah -- plenty of choices here. Wherever you do end up playing Limbo, make sure you've got a setup that'll do the audio design justice. Having recently gone back to play again, I forgot how brutal it can be. There goes my head!