Yeah, it's a LOT of fun. I've played through the Story Mode completely three times now (once the first time, once to get Test of Faith -- don't shoot any enemies, and once to beat Hard Mode and get Pro Runner), and it's become more fun now that I know better where to go.
The theme is awesome -- I can't decide whether the instrumental version (Shine by Alcorus) or the lyrical version, which I'm assuming is the one you've heard -- Still Alive by Lisa Miskovsky -- is better. My only issue is that, at the beginning of the short cutscene of the Prologue (the actual cutscenes which look very meh compared to the rest of the game, despite the fact that it's usually the opposite, are there in addition to a short CPU-controlled part at the beginning of each level, which is what I'm talking about), there's a version of Shine which sounds awesome. But I've found two different versions of Shine and neither has the exact same sound as it. You can hear what I'm talking about starting at about 1:32 in this video until you hear the signature...whatever that instrument is that they use throughout Still Alive.
Faith is fairly attractive (for a video game character, anyways), but don't let that get you into the game since you only see her full body in high quality in like, the final cutscene (which is one of the CPU controlled ones and then moves out to third person).
But yeah, it's an awesome game. What are the specs on your computer? If they're good enough to run the game without a lot of lag (otherwise it'd kinda ruin the game, especially when we're talking about a game like Mirror's Edge), I'd suggest getting it for PC. If not, well...I'd save your money up for another console anyways, since the Wii is very meh.
My point is, if you can, I'd DEFINITELY get my hands on it.