I want to like this book better. I really do. It's got a good, intuitive game system. It lets you play just about anything. It doesn't take itself too seriously. It's clever. These are all very, very good things, and you should seriously consider buying this game because of them.
On the other hand, while the game is very clever, it's not especially funny. This is a very, very bad thing, because the game so desperately wants to--and deserves to be--a comedy. But comedy is damned hard to do, especially when you're laying out a system of dry, probabilistic mechanics and writing up a campaign setting that the characters are supposed to take seriously, even if--especially if--the players aren't. For whatever reason, this book just can't take itself seriously enough to be a good comedy. It should be a simple matter to make a Demon Hunters game into a rollicking fun time--that's just the DM'ing part, and that's all in timing and delivery--but it still feels like the authors are passing the buck on to someone else.