This movie is a classic example of a great idea suffering from low budget. It is like a B-movie by Tarantino. Or Kevin Smith maybe. Or a crossover of both meeting a film by John Carpenter. This is definitively a B-movie of some sorts, but a well-made one.
The whole thing is a bit strange (which in my opinion is not a bad thing), and the characters are... well, unusual. And the story has a nice twist to it. Many, many good ideas, although violence and humor are not always too well-balanced: sometimes they simply clash. But at the end, it works quite nicely. Don't mind the few gaping holes in the plot, just sit back, relax and enjoy the ride.