From The Psychotronic Video Guide by Michael Weldon:
D/S: Robert Hiltzik P: Michael Tatosian, Jerry Silva. In a nasty Friday the 13th rip-off that’s better than most, campers are killed in upstate New York. Melissa Rose is the shy murderous Angela, and there’s a Homicidal-style sex switch involved. Ed French created the grisly FX. With Mike Kellin and Robert Earl Jones.
Reviews that peg Sleepaway Camp as a Friday the 13th ripoff are a dime a dozen – and they clearly signal reviewers who either didn’t actually watch the movie, or only vaguely paid attention. It’s such a broad statement to make when even the film’s superficial elements barely compare. For specific points, I suggest you read: