This movie is the essence of an escape movie. It has some of the most nail-biting tension put to film (thanks in part to the relatively bare soundtrack). It has stripped all the excess and fat off of it (such as a background story and characterization) in order to focus solely on the details of the escape. The shot composition is pretty incredible (made more impressive with long tracking shots).It would be a pretty terrible movie if you can't get into it, since the entire movie is basically details and nothing else. You just need to know what you're getting into. Lucky for me, I was enveloped from the second it started.
IMDb link: http://imdb.com/title/tt0049902/