This is the worst movie I've ever seen. I don't say that lightly. It isn't hyperbole. I generally love bad movies, and I was even watching it with a buddy of mine who loves bad movies too, but this was the most unenjoyable movie experience of my life. Don't watch it.
Nothing in this movie matters. If you think something in this movie mattered, you are wrong and you should rethink some things in life. Spoilers, but every single set up in this movie is a red herring! My friend and I were pointing out things that we thought were gonna be relevant later - the main character's running, his poor eyesight, the mom's photography, the location of the neighbor's house, the water heater malfunctions (that were actually just there to establish the basement being creepy and to give an excuse to show the mom's butt), the reveal that the main character's dead dad was kind of inadequate, the killer getting in bed with the mom before killing her- but no, none of these things matter. The killer is a random dude who kills people by using open houses to gain access to their homes. The thesis of the film is just "hey, open houses are kinda creepy, huh?" Halfway through, the main character starts monologuing and I said "ooh, here it is! Here's the thesis!" but then his monologue amounts to "hey, open houses are kinda creepy, huh?" and I was like "nah, that's way too dumb to be the thesis, this is just to set the mood." Nope. It was the thesis. Aside from that, nothing else matters. This movie pretends to be interesting and then none of it matters and the title is way too literal and then the movie says "bet you didn't see that coming" but the reason that you didn't see it coming is that it was dumb and bad. It's not bad in a fun way. It's just irredeemably bad.