Before I begin this review, let me warn you, there are spoilers. If that doesn't bother you, please read on.
There's a reason why I don't rush out to the theater to see movies where the person is possess by some kind of evil spirit or demon. The reason is... the characters are never practical. I've just watched the "Possession" and like most movies with this theme, there was a lot of loud noises, creepy shadows, people walking around in completely dark rooms and refusing to turn on the light... seriously, what is everyone's aversion to turning on the damn light?
Nothing really scary happened in this movie. So either I'm completely jaded to evil spirit/demon possession movies, or Hollywood has lost it's touch to scare its audience. Either way, I was pretty bored with it. Another thing I don't like is the fact that characters don't explain themselves the way they should. A little explanation can go a long way and would get things moving a lot faster by way of getting an exorcism on the agenda.
Also, I hate when the lights flicker or go out completely and then something drastic happens but you as the audience didn't get to see how or why. This is a cheat and it cheapens the movie. Apparently, the director/writer didn't want to explain how the ghost switched bodies, or why, since we're told that it's a spirit that devours children. Why would it want the body/life of her father when it was pretty much fully bonded with the daughter? And how did it enter him? Didn't get to see that part, because the lights went completely dark and then the scene was switched without any explanation whatsoever.
It had the potential to be good, but it wasn't.
C-, I'm assigning extra-credit homework.