excellent movie

Why on earth does this movie get so many bad reviews? Having read some of them I expected a boring and incoherent plotline, and found myself surprised by almost 90 minutes of excellent horror/mystery. AND: there is a message underlying the whole plot (at least this is the message I got out of it): 1. Don't ever get yourself involved with somebody/something you don't fully trust. 2. Even the weakest of light is able to disempower darkness!! Absolutely recommendable!!!