I recently managed to grab Limbo (and a few other excellent videogames) as a part of the 5th Humble Indie Bundle. I’d seen Limbo long before HIB5, but back then it’d only been released on XBLA, which is why I was overjoyed to see it on HIB5 (which usually means Linux compatibility.) Unfortunately it appears that the Linux version is a simple WINE wrapper over the Windows version. Either way, I had to have a go at it (on my dad’s laptop which still runs XP.)
Limbo’s a monochromatic platform-puzzler with an interesting sense of design and a macabre sense of humour which involves having your character impaled by spikes, decapitated and eaten by a spider (among other things) while you try and figure out solutions to its puzzles. It’s almost like Braid in black-and-white. I’ve had a lot of fun with it so far (and I’m about 70% through.) Go buy it if you haven’t bought it yet — it’s totally worth it.