Good story, Not enough for a whole film

It's funny, it's tense, it features two great performances from two actors and the director expertly creates a web of odd tension where you actually don't know what is happening for the majority of the run time.

It is neither dumb nor smart enough to be fun, and spends way too much time with its boring human characters.

Exactly the movie you think it is, but not the movie you want it to be.