The problem with the majority of horror movies, and why I dislike most of them, is that the writers are so lazy or inept at character creation. Instead of drawing us into the film we're too often pushed away by their complete lack of human qualities to which we can relate; logic being the most neglected.
A horror writer may be skilled at fantasizing a scene or story that is scary. However, when creating the character with whom we should follow into the horror fantasy they too often fail. They resort to having the character make completely stupid or illogical decisions in order to place them in harms way, and keep them there. This makes me want to scream and storm out of the theater or burst out laughing.
I did much more laughing in this film. While the story and plot twist is pretty good the main character's actions are inexcusable. When a psycho killer is slowly approaching you with a knife a logical person will not stand and wait. Also that person will not run a short distance then wait for the killer to catch up. This movie should have ended way too many times but instead the cheap thrills just kept repeating themselves.