I usually don't comment what fellow critics on IMDb write, but giving this little masterpiece only an average of 4,2 is bad taste indeed. In short; it's been a while since one saw a movie there so much happens, even if you don't see all of it on the screen. Franziska Weiss is really great, with a face which tells you a lot, with just a small correction of the glimpse in her eyes.
This is creepy, but in a way you might be rather familiar with from your own life. That life is here, by very small means, a nightmare. Maybe the end doesn't really fulfill what is promised, not really. Maybe the camera spotlights in the forest surrounding the hotel are too sharp.
But still this is supposed to give you much worse dreams than for example "The Grudge", which is made by amateurs.