★★★½ (3½ out of 4)
The menacing, mesmerizing mind teaser that is “Backrooms” has its work cut out for it. The film’s 12-year-old director Kane Parsons (OK, he’s 20, but you get my point) thinks he can challenge the horror audience instead of just coddling it with blood splatter. I think we can all agree that the part of the brain that controls thinking does not get overworked by Hollywood. Yet “Backrooms,” for all its unnerving suspense, is an intellectual puzzle devised by a visionary trickster. Let’s say this about Kane Parsons—he’s diabolical.