i downloaded a demo for it on xbox live not too long ago. it seems pretty entertaining, it has a reflex-driven turn-based combat system (similar to games like Paper Mario) and can be played in a co-op mode, from what i can understand. the humor's mostly hit-and-miss, and the demo did have an obnoxious narrator acting as a tutorial. overall it seems like a pretty good game, but $20 for an xbox live game is a little much for me, especially if it's only "part 1" of a series that will supposedly run to either five or six.
i think it's pretty solid, but i'm only judging it on a 20-minute console demo, i have no idea what it'd control like on a PC.