"Based on a joke once told by Jim Wynorski"... that's what I've read at the end of the closing credits. Well, Mr. Wynorski gotta have an awful sense of humour then! This film is terrible, really. I loved the first two chapters of The Slumber Party Massacre series; the third film was quite useless, but completely watchable, compared to this piece of crap! There's not even a Driller Killer and the plot, the acting, the characters, the locations, the events... everything is boring, absurd and laughable. The only good reason to watch this turkey are the girls: if this film were a porn, I think it would have worked really much better! The film lacks gore too: the first scene (the one in the tent) could be bloodier and the scene with the headless guy knocking at the door lasted one second! Some moments of slight thrilling can't save a nonexistent plot. Buzzy (Lunk Johnson) seems to be the only real actor here: I found him the only bearable character in this movie! Oh... there's a nonsense part with Brinke Stevens, who performed "Linda" in the first Slumber Party Massacre: the police bother her to know more details about the killer; but what we get is only some footage from the first film! Not a dialogue, neither a monologue, or anything from this still-traumatized grown-up girl, who's forced to revive the worst 30 minutes of her life (as she says), giving us no clues at all about the murderer!
Watch at your own risk.