This is a haunted house story, plain and simple - but it's refreshing to see one with a decent cast and so well executed. The story is nothing new - family from the city move to country to escape their family problems... house they get turns out to have a past, and may be haunted.
There are no big gore moments, but plenty of atmosphere created by carefully NOT showing you everything for much of the movie, so that when something is seen, the effect is maximized. The ending is not much of a surprise, but the tension mounts thanks in particular to a good turn from Kristen Stewart as Jess, the teenager.
All in all, quite routine, but efficient enough to be worth a watch if you like the haunted house genre.