Pretty solid, liked it enough to get all achievements. The late-game could be better(enemy variety, story rushes itself, exploration being rather fruitless later on) and it's very easy to get obscenely overpowered if you're a more thorough player. Post-game is pretty cool but doesn't have too much content going for it.
Judging by how piss-easy the game gets, I imagine this has a BBI-esque expansion that was being worked on simultaneously with core dev but we'll have to wait and see.