Not bad!
I saw it today and it actually was pretty good. Some parts were scary, and the vibe, in general, was creepy. They also threw in some comedy a couple of times. Acting was great. It was definitely very original.
There are a couple of unanswered questions but that's typical in movies nowadays.
I think any horror/thriller fan will enjoy this movie.
Edited: I forgot one important detail: The music was fantastic and added to the creepiness.