This movie was pretty hard to take at times, with the level of violence and bad language. But, the acting and film-making was so good that it held your interest. The aspect of the movie that appealed to me was how engrossing it was at presenting a group of people trapped in a house together with time running out and none of them trusts the others. The way these people talk to one another is hard to take, there is such an undercurrent of - not hostility or distrust - but out and out evil. When one character talks about "dumping these two in the river and getting out of here", you actually shudder when you find yourself agreeing with him, not from a humanistic standpoint, but because it's logically the best thing to do.
This movie is, in a way, the quintessential no-budget movie: A lot of raw talent using less than no resources, and making a very watchable movie for a select audience. You just have to decide if you are that audience.