Before I begin, I should warn that there are spoilers here. To summarize the story down to a point where there would be none is basically just the first fifteen minutes: There's a guy on the moon for three years, under contract from a big corporation to mine Helium 3, which is solving all the world's energy problems. He has a robot friend. Now, I don't think that's much of a summary, especially since even the trailer gives more away, but I'm very sensitive about things being spoiled for me, and I wouldn't want anyone giving away anything more than that if I hadn't seen it. So there will be a section that mentions more of the story, clearly marked and towards the end. Be careful where you read. I have also seen it several times before, so I've had time to go crazy about it.
I love this movie. Let me explain.
Movies with small casts are great. There are less characters to keep track of, which is good for audiences because no one gets confused, but it's also good for writers, because fewer characters means fewer connections and relationships to make, as well as allowing for both more and better interactions between characters, letting them develop the way they should. Moon has two characters, three if you count the robot.
Movies with few locations are great. Again, there is less to keep track of, and the less time characters spend going from one place to another, the more time they have to develop. Developing characters is paramount. Moon has two locations: in the base, and out of the base.
Science fiction movies are great. They are always good at making solid political, religious, or social commentaries, because they allow us to examine ourselves on a subconscious level. Rather than look at the Iraq war directly, we have Battlestar Galactica; 9/11 is substituted with Cloverfield; South Africa under apartheid becomes District 9. While science fiction movies are not intentionally based on events (with the probable exception of D-9), they do have undeniable parallels.
Moon does the same, posing questions about not just the ethics of cloning, but the moral issues of how we deal with clones. Can we justify making people? Do we overstep our bounds and challenge nature by cloning cells for medicine, or organs for transplants? Beyond science, how do we deal with clones? Should they receive the same rights as people born naturally, or is it socially acceptable, if morally reprehensible, to exploit them? We certainly feel for the two clones, especially the one whose contract is almost up. One of the most devastating scenes has him talking to his daughter, finding out his wife is dead, and crying, saying, "I want to go home," when there is no home for him to go to. He was revived with the memories of a life he never had. What's sadder still is imagining the clones before him not even knowing what he knows; they all climbed into that insta-cremate machine, expecting to return home, only to be killed. They knew only a piece of Sam Bell's life, and could not live any more.
I can say without hesitation that this is my favorite science fiction movie. As much as I like Empire Strikes Back, Moon has so much more heart in it. So much care was put into it, every shot was poured over, and everything fits perfectly. I cannot say enough good about it. It has a solid place in my top five, sitting at number two right under Fellowship of the Ring. And with a little more time, it might take number one.