This is a movie that makes some fairly bold directoral statements early on. However, I'm not sure those gambits ultimately pay off. For example, fixed distance shots do nicely illustrate group dynamics, and create an increasingly bleak picture, but don't allow sufficient intimacy with the characters to sympathise with their situation.
We're initially introduced to Robert as a talented cellist with a penchant for cannabis - however, that's the only real detail we get. The film wastes valuable minutes on trivial scenes (for example, flirtatious schoolgirls making a play for their teacher - limply played by one of the current Eastenders cast), when it could be painting a more complete picture of Robert's progressively harder drug use, or the emerging psychosis that would legitimise the violent act he commits at the end.
As it stood, there was not enough character development or empathy with their situation for the ending to be anything more than gratuitous, and yet strangely morally indecisive. This was a shame. The theme of sexual violence (and its consequences) was well dealt with earlier in the movie. Pretty much anything else would have ended this film better. Additionally, no part of this work was worthy of comparison with Clockwork Orange - as so many reviewers have suggested.
Drawing a line under all that, there were some interesting and enjoyable parts. However, while initially compelling and engaging, it was ultimately disappointing.