I recently re-watched the original Friday The 13th movie, in bits and pieces over the course of a couple of nights. While watching the last 20 to 30 minutes separated from the rest of the film, I realized something that I really like about this movie – the killer is a normal looking, older woman. Not supernatural or super-powerful or something that is obviously scary.
This gives the film a level of horror beyond just the slasher scares of the murders. She's a regular person who, through losing her son while attending Camp Crystal Lake, is pushed over the edge and lost her grasp on sanity. This could be anyone – through the right circumstances just about anyone could be driven to that sort of insanity. And there's no way to tell who could or who already has, they don't put on masks, aren't deformed, or horribly scarred – their scars are invisible. This underlying fear that anyone could decide to kill you is completely terrifying and grounds the terror in something very real and innate in us.
It's too bad they basically undo all of this at the very end just to get a cheap, quick, jump-scare. The movie has no supernatural elements to it but then, what we are to believe, the undead corpse of Jason Voorhees jumps out of the lake and grabs the lone survivor. Sure, it's a good scare you don't see coming, but it's out of place with everything else that happened so far, it's clear the filmmakers just felt the need to add one more thing at the end. If they didn't have this last bit, the film could have a very solid sense of existential fear to go with its slasher kills.
