The way the movie ****ed with your head. (SPOILERS)
This movie was disturbing in the way that it made you think, for extended periods of time I might add, that something horrible was going to happen to people that other films would consider taboo. It made you think that a whole elevator full of pregnant women were going to die, or that a little girl was going to die.
It was disturbing not in the usual fun sort of way but in a way that was more like "oh this movie better not go there" kind of way and was later proven positive when it killed an entire elevator full of people by dropping the floor out, including children...not cool.
I don't usually get freaked out by the violence in horror films but this one really got under my skin for some reason and some of the images will not soon leave my memory.