When this movie hits, it hits the funny bone right on. And on the balance there's a lot more hits than misses with this movie.
The humor is often juvenile and obvious so don't watch this if you want subtle or wry. I think many females will enjoy this movie just as much as males will but the sexual humor makes it seem targeted to males of a certain demographic. What females will like is the female character portrayal gives as good as she gets. And the one liners are really funny.
The cast for the most part is well chosen, and their character's quirks all bounce off each other nicely. The only miss in the cast department is the government watcher guy, not that he was bad but in a movie like this where everyone is basically insane you kind of need even the straight characters to be a little deeper. I really liked Alien Jesus also.
This is a low budget movie, glaringly obvious, but at the same time it's basically dialog driven comedy so who cares really. It's just a fun movie, not a classic, but not bad.