Bad watch, probably won't watch again, and can't recommend unless you're ona Simon Pegg binge or an eccentric writer.
I like Simon Pegg, but this doesn't feel like one of his movies, and maybe that was the point.
It has an interesting premise, and maybe I wasn't in the right frame of mind for the movie, but I don't find the paranoia and mental afflictions of the character funny: I don't even feel they're presented as jokes.
There is some heavily worked situational comedy, but the movie doesn't feel like a comedy itself.
Long story short: it was kind of a depressing watch with some mildy interesting psychology to it and rather little criminology.