I find it hard to define science fiction but I do appreciate if there is a scientific element to it.  I know that "Star Wars" is misclassified as "sci-fi" because it has lasers and space battles but it's really more of a fantasy whereas movies like "2001: A Space Odyssey" and "Primer" feel like real science-fiction.  But where sci-fi becomes great is not just incorporating scientific ideas or conundrums, but in seeing how that science reflects or explores the human condition.  "Moon" is true and great sci-fi and it's a refreshing film in an age where sci-fi has come to mean "Transformers" and "Cloverfield" (two enjoyable flicks, but not science-fiction)

Astronaut Sam Bell (Sam Rockwell) is nearing the end of a three-year contract for mining renewable energy from the Moon.  Bell's only companion is a HAL-like program named Gerty (voiced by Kevin Spacey) but he seems to be holding his sanity together.

And that's all I can say.

"Moon" is a film that once spoiled will significantly lessen its impact.  However, do not be mistaken (as I was) that this is a film filled with twists and turns and attempts to mindfuck you.  There's one big twist and it opens up what the film is really about in both narrative and theme.  However, do not expect twist after twist and instead appreciate what the film is trying to do on its trajectory. 

In addition to not being a mindfuck, "Moon" is not as dark as I expected.  A guy living alone on the Moon with only a HAL-like computer for company seems made for some serious depression but there's not only humor in "Moon"; there's hope. 

But since I can't really talk about the movie without spoiling it, let me talk about what works in the film other than the narrative.  Sam Rockwell is, unsurprisingly, magnificent.  I've been enamored of Rockwell's acting ability since "Confessions of a Dangerous Mind" and even though he's really the only actor in the film (there are a couple actors scattered throughout the film but they barely qualify as supporting roles), you don't really need anyone else when you've got Rockwell.  Spacey's good as well, providing his own touches to Gerty and pays homage to Douglas Rain's unforgettable HAL-9000 vocal work rather than just providing mere imitation.

Director Duncan Jones has done an amazing job on this film, not just with his lead actor, the pacing, and the story, but in designing sci-fi without a massive budget.  Jones understands that sci-fi isn't in the big special effects but in creating a convincing environment and everything from the moon base to the vehicles to the costumes feels wholly authentic and not like futuristic concepts from an already dated future.

"Moon" is sci-fi as it's meant to be and while I wish I could go into greater depth about why that is, I'll just ask you trust me on this one and say that if you love classic sci-fi, you owe it to yourself to see this movie.