I can understand both sides of the rating here, its definitely not for everyone, but I found the horror elements quite suspenseful, not high on jump scares but atmosphere was on point. The narrative structure is non-conventional which I think threw some people off, but I thought it was quite well executed.
Story could have done with more fleshing out which would have really elevated it overall, but the suspense of who the antagonist was at the start was quite a ride. Acting was great, just let down with some decent but not fantastic script writing, but acting, directing and cinematography I rate full points.
The themes explored I interpreted as exploring the types of evil - nature, nurture, and opportunity and to some extent circumstance which again reading the comments seem like confused a couple of people.
Probably as far as I can go without spoiling anything, but honestly I thought it was quite a good movie. Just could have had a bit more of a developed story to explore the characters more and scripting more believable reactions (ie the cops).
Wont win an oscar, but I finished the film quite satisfied as a horror enthusiast