For those who don't know, "Still Alive" was written by the esteemed Mr. Coulton for the game "Portal". Yes, I know, it's nearly 2012 and everybody should know that by now, but I've already seen people bitching that this song is a rip-off of the free version (which is the version from the game itself, as sung by GlaDOS).
This version features brand new instrumentation, new vocals from Sara Quin of Tegan & Sara, and comes with a keyboard track and harmonies. Harmonies! As someone who tends to sing the harmonies to this song anyway, I'm quite happy about that.
But enough of that. How's the guitar? Well, there's a lengthy Theremin solo at the start of the song which is oddly played on the guitar rather than the keyboard (the keys are otherwise occupied at this point). After that, it's business as usual - the Theremin does reappear later in the song but it's handled, more appropriately, by the keyboard.
Once the song gets going, the guitar track is more or less the same as the track from the original, but with enough variation to keep you occupied. It's perhaps a little easier than the free version - anyone buying this expecting a challenge will be left disappointed (but then, nobody plays "Still Alive" for the challenge, do they?).
All in all, this is a rather brilliant and inventive arrangement of a well-worn song - not necessarily better, but different. Personally, I love it.