The first half of the film set the scene and began to explore the social and political aspects of a vampire race that had almost extinguished its food supply and was facing imminent destruction unless they could come up with an alternative.
I found this intriguing as it is something that doesn't often get mentioned in vampire films i.e. humans being killed all over the place and nobody ever has anything to say about the number of human deaths in bizarre circumstances. Also, if you've got thousands of vampires hanging around and they are chowing down on a human a day, and also turning humans at the same time, eventually the ratio of vampires to humans is going to change.
So, the first half of the film I thought was really interesting and thought provoking, and I'd give it 9/10.
Onto the second half of the film. Basically....the writers went home, or started drinking or something. All of the well thought out plot setup of the first half just descended into guns, fighting, and even a bit of deus ex machina. Not much else to say on this half to be honest, I really lost interest. 5/10 for this half.
So overall, 6/10 for the whole film. It was definitely worth watching, but was just a real shame that after, what I thought was a great premise, just trailed off into a lazily written ending.
Just the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.