It's entirely possible that sending the audience out feeling lousy was intentional

The film creates a perfect balance between action and depth of basic needs, in the midst of an infertile atmosphere.

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.

The film never slows down or bores, plunging from one harrowing sequence to the next.