Ok so basically, the film is about human nature and instinct and what people really think when they really need to make a life or death decision. The ending is pretty obvious as I saw it.... He joins the rest of the victorious few and they will then be pitted against one another to have a final winner, hence why the alien craft was making its way towards them at the end. He realised that what he had done had made little or no difference whatsoever in what was clearly an experiment from a superior race. Good film in my opinion.
