I've been laughing my ass off for the first few hours of the game, and I think the gameplay, while not particularly great, isn't bad either. 
It's becoming sort of like Deadly Premonition to me, where the point really isn't the gameplay, but in the personality and in the detailing. Somehow, hearing people complain about the gameplay of the game almost pisses me off. There's some real snobbery to bitching about the "bad shooting" in a game where you can draw a dick on a kid's book. 
 
I think, in short, if you got a kick out of bad movies in the past, like Dead Or Alive or Piranha 3D, then you should get some nice happy times out of DNF. If you think those movies are for idiots, then don't bother.

Gotta say I agree! I could never call this a good game but i haven't been bored yet! 5 hours in.