Moon's brilliance is in its thought-provoking, heart-breaking premise. This is a tragic psychological drama, where Sam discovers that he isn't alone on the moon and, ultimately, that he isn't real. He is a fabricated clone of a man who once worked for the same company he does, and his dilemma shifts from longing for his family to wrestling with the reality that his identity is completely artificial. He is isolated, alone and left to reconcile that neither he or the relationships he clings to are real. He also discovers that because he knows the truth, the company will send mercenaries to kill him before their secret gets out. Ironically, he finds company in a fellow, identical clone of himself, who work together to discover the truth and eventually escape.
One of the more interesting aspects of the film was the interplay between the two clones. Sam Rockwell creates an incredible and intense performance by playing two versions of the same man, often facing off against each other. One is a goofier, more aloof man, made delirious by his isolation and work. The other is a fresh clone who is tightly wound and angry, ready to work. The two argue and bicker and eventually come to an understanding so that they can survive. I think the camera work and special effects were ridiculous. I have no earthly idea how they were able to have shots of Sam Rockwell playing ping pong with himself, crossing over himself, even talking to the other man in simultaneous still frames. It was a sad, but rewarding intellectual experience.