What people have to remember is that the "horror" in this film is all psychological. What is scary about it, is 'what you can't see'. If "what you can't see" doesnt scare you and you are more frightened by blood/guts/gore, then this will film will seriously dissapoint.
Personally, I've grown up on a diet of guts/gore horror movies, so they don't scare me in the slightest.
Paranormal Activity on the other hand, worked very well for those of us who are frightened of "what you can't see".
Another aspect of this movie's horror is that if you are watching it with a group of other people, with the lights on, I honestly can't see it working as a horror movie. Most of the attacks of the movie occur at night and if you watch it with the lights on or in daylight, then it will lose its scare factor.
One of the scariest films I've ever seen is 'The Entity'. Nobody dies in that movie, but the problem is that nobody can actually see 'The Entity', which is what makes it scary.
