The three performers do quite a good job of portraying friends, although there is some competition for Dan's attention between his longtime pal and his girlfriend. It is a dynamic that feels very true to the situation and actually changes over the course of the film. As good as the three are, it is Emma Bell who delivers the standout performance. There is something genuine about her approach and how she delivers her lines. It cannot be easy to make this claustrophobic film work, but they do it.
Adam Green also deserves a lot of credit for writing an effective script and making everything interesting. He manages to keep you on the edge of your seat for a lot longer that I would have initially thought possible. It is not the most dynamic of movies, but Green successfully builds tension and conflict with believable outcomes.
Bottom line. This turned out to be a lot better than I was expecting. A simple concept was taken and built into a film filled with terror and dread. You will be guessing just what is going to happen next. I felt the characters' pain and never want to be a in that sort of position. Makes me glad I am not a skier!