An 80s slasher called sleepaway camp. It doesn't sound anymore generic then that. In some ways it is, however, there is more beneath the surface. It's also very watchable as the characters are good and the slasher mystery works.
There is a big clue as to the killer near the end which gave it away for me a little. The ending I also predicted may happen (my twisted mind) but I disregarded it as I thought they wouldn't have the ...balls?... to pull it off. Well they did. I must admit I laughed quite a lot at the end. I imagine in its day it was creepy. What makes this better than most slashers is 1. the fact that you'll remember it. And 2 is.... thinking about the movie after. When I did this is went from a 6 to a 7 rating as the hidden plot gives the movie another layer and also a re-watch value that it otherwise wouldn't have had.

So what the hell happened? Well Angela is a boy who's father and sister died at the start. She goes to live with an aunt. During the movie Angela has a flashback of men having sex (her dad is one male) as she/he/Angela spies with her sister ..
Now Her Aunt. She wants a girls as she has a boy so makes Angela a girl. Weird. She did this to Angela just after the accident and when she was grieving. Was Angela also abused in the flashback? Not sure.
So the camp is too much pain for Angela with the bullying and the molesting head chef. Angela goes crazy. But wait.... more...
Is it me or did her aunt look a bit like a man? She dressed overly female and had exaggerated mannerism like transvestites sometimes do. Also wasn't that Ricky in the doorway wearing a wig about to kill Judy? He was! Was he born a girl? If the aunt is messed up to do it to Angela it's likely. In the flashback a boy and girl are pointing at each other as if to say they are the others gender. Maybe. Also did Mel know Ricky was one killer? He said he'd seen him around and was positive. Man this movie is real bizarre when you think about it.

One more odd thing.... If aunt Martha is a man.. she looks very simular to the man that slept with Angela's father.. but I'm sure the look is coincidence. Angela's father at the start mentions Ricky's father. We never see him?
This could be the sickest and strangest movie I've seen in a while .