New version of psycho anybody?

Undoubtedly the movie has a very intriguing 30 minutes at the start. And as a viewer I was excited to see more sinister revealing of the crazy guy. I predicted the entire movie was going to be shot in the same house. But I figure that was going to be pointless as the house guests were imaginary. The character was played terrifically. Somehow his bizarre character traits did not seem to match with his role of playing a cop. A majority of his insane actions appeared baseless and did not support the proceedings in the second half. It's like saying that this guy is mentally unstable, but he's a great cop. I accept the writer attempted to do something out of the ordinary, but everything has to have a meaning. The final half hour is acceptable. However as none of the two characters met fate, it kind of leaves a sour taste. Interesting concept none the less