The movie subtly darkens its tone until, when the horrifying ending arrives, we can see how we got there. There is a final shot that would get laughs in another kind of film, but May earns the right to it, and it works, and we understand it.
Call it a horror movie, a psychological thriller or a feminist splatterfest, but this sort of story is tough to get right. May gets it more than right.
Satisfyingly, May also turns out to be lowdown genre fun, a film that nearly makes up in slacker wit and high-spirited gore what it lacks in budget and elegance.
Led by Ms. Bettis's discreetly campy May, the performances are a cut or two above what you would find in the average slasher film. But in the end that's all it is.