More silly than scary, this horror comedy is more Meatballs than Friday the 13th, a playful stalker mystery that nevertheless is not quite a spoof of horror movies. The madcap storytelling keeps the characters and audience guessing with modern twists, satirizing fad diets, our dependency on our phones, and our natural inclination to overinterpret text messages and social media posts. The setup has fun by knowingly piling on horror cliches like the sleepaway camp being at the site of Indian massacres, witch burnings, and having at least one unexplained camp attendee disappearance. It’s a small budget effort with a limited cast and a single setting. Good for a slumber party with friends who don’t like anything too scary.