Now that the horror genre is seven Saw movies deep, it might seem like there’s nothing that could be done to possibly shock fans. The last decade’s foray into torture porn has emphasized the fetishization of suffering over suspense and existential dread, and piled on the gore so thick that no part of the human body has emerged unscathed.

Thanks to the brazen novelty of its premise, The Human Centipede — out today on DVD as an unrated director’s cut — succeeds in not only differentiating itself from the glossy, contemporary crop of Hollywood horror, but manages to wring a surprising amount of humor from its sadistic plot. The independent film centers around a crazed German doctor (Dieter Laser) who kidnaps three people and surgically attaches them via their gastric systems to create the titular creature. There are no subplots to be found here, only the shocking, central story of a crazed doctor and his medical atrocity.

The centipede itself consists of two American tourists (Ashley C. Williams and Ashlynn Yennie) as the middle and rear segments and Akihiro Kitamura’s loudmouthed Japanese businessman at the head. During the film’s dialog-heavy opening sequences, Williams’ and Yennie’s acting is shaky at best, but the two fare better once wide-eyed terror and disgust are the only emotions they’re expected to convey. (This raises the age-old question: is it easier or harder to evoke an audience’s sympathy when your mouth is sewn to another actor’s anus?)

Throughout the film, writer/director Tom Six treads the line between comedy and horror. The no-frills story builds to an entertaining confrontation between creator and creation then, in a nifty turn, gives way to a haunting, emotional monolog from Kitamura, who proves to be an unexpected source of pathos.

Given its self-amused depravity, The Human Centipede is a difficult movie to recommend, yet also a surprisingly easy one to enjoy. Six stretches the movie’s limited budget as far as he can, confining the action to the opulent claustrophobia of the doctor’s house. Yet, despite the clever use of space, the bare-bones plot is scarcely able to fill the 92-minute running time.

The Human Centipede pretends to be some kind of literal manifestation of the dangers of forming human attachments but, given the absence of any real character development, the claim rings hollow. Had Six endowed his victims with more fraught, psychologically complex backstories, it could have shed a more interesting light on their predicament. Despite those shortcomings, the film does manage to create a bizarre, twisted nightmare out of some unforgettable images, and at times even conveys a palpable sense of dread. And, for better or worse, that’s more than the Saw franchise has accomplished in seven attempts.