Well, you've already pointed out the main problem, being the lack of story. Some dude in a creepy house who gets attacked randomly by a psychopath. Part of the problem also, is that it all happens so fast, we never have time to absorb what is happening. Especially at the end when you have that sequence of short cuts and then all the sudden he is dead. I kind of has a "lolwut" effect.
But there are definitely good things. The animation was good for the most part, and I also thought that the lighting was effective. And like Jargon said, you could feel the fear there, it just came and went too quickly to have the desired effect. But it was good overall.