I don't know how a small game from a new studio (albeit founded by Halo's daddy) scores a soundtrack like this, but I'm OK with whatever they had do (hey, it doesn't affect how I sleep at night).
The soundtrack is basically covers of 50s songs, and is absolutely brilliant.
Since Stubbs the Zombie (the game) is set in a utopian future -- but a utopian future from a 50s perspective -- covers of 50s tunes by today's artists (and top hanger-ons) like Ben Kweller, The Raveonettes, Death Cab for Cutie, The Dandy Warhols, The Flaming Lips, and others totally fits the vibe, and the tunes are slick.
Really, only Rose Hill Drive's "Shakin' All Over" and Phantom Planet's original "The Living Dead" seem a little disjoint from the rest of the album. Hey, are Phantom Planet's whores for soundtracks or what? (I mean "whore" in a good way. Hey, as an actor-slash-comic book junkie, I'd be in every comic book movie if they'd let me; but Mr. Lee never calls.)
The other thing I really appreciate about this album is the audio quality -- the sound is crisp, and pretty normalized (but not muddied) across tracks. Not like The Punisher Soundtrack.