And it is a trip. I don't have much to complain about. The movie was horror through and through with an interesting twist in the end. It also left me thinking about it when it was over (if you watch it, look for the name of the last train station.)
They did some wild things with the cinematography. Stuff I haven't seen in a movie before. I came away with some very disturbing images - and not just because of the graphics, but because of the horror of the circumstance. It's not "torture porn"; it's way better than that.
It's not the greatest movie ever made; but it's definitely worth the rent even just too see the special fx.
(note: the unrated version has a cartoonish amount of blood. Japanese director, go figure.)