Only real payoff is seeing the monstrosity assembled, and though that will surely earn the Dutch writer-director a cult reputation on the genre circuit, "going there" does not a movie make
More of a stunt than a script, The Human Centipede (First Sequence) should get a modest amount of I-dare-you ticket sales, but it's about as mass market as a dogfight
It's definitive psychological horror, positioning the viewer to identify with the victim's suffering and lack of free will, even after harshly judging what they did with that free will when they had it