I watched the trailer on the DVD after seeing the film, and I think anyone who saw it before watching the film would be very surprised and possibly disappointed. It made much of the fact that the film was "by the director of Cube" and made it look like a horror film, when in fact it is an Absurdist comedy (IMDB's spell checker doesn't seem to think that Absurdist is a word, but it is), reminiscent of Rosencrantz and Guildernstern are Dead.
I love the way the story builds up slowly at first, then gradually escalates. I also enjoy the fact that no explanation is given for what happens in the film. That and the fact that the story plays out mainly in just the one set are the only respects in which this film is similar to Cube. I recommend it.