The characters are all overexaggerated and so off-the-wall it's hard to look away. The story is gripping, pulled along by this rag-tag group of people with increasingly diminishing morality. While everything else is a bit cheesy, the core premise and explanation of the vampires is actually very cool. The imagery is really visceral and often quite gross (especially if you do not like worms). A really interesting and fresh take on vampires with roots in the traditional mythology.
Don't think too hard about it, and you'll have fun. I can't recommend it enough.