Moon is an average science fiction movie in the same vein as Stanley Kubrick's 2001: A Space Odyssey. The plot follows space miner Sam Bell (Rockwell) and his robotic assistant Gerty (Spacey) nearing the end of a 3-year stint on the moon. After recovering from an accident, his body begins to slowly weaken and degenerate; he experiences hallucinations, vomits up blood, and loses his teeth. And that's not even the weirdest part.
The plot is interesting, to say the least, which is why I wanted to see the movie. But it failed to live up to my expectations because of atrocious pacing. There was no build-up, climax, or denouement. The movie peaked about halfway in, and after that you just sat and watched events you don't care about transpire. Without any prospect of progression, the audience will find the movie boring and slow, which is what I found it. (I even caught myself nodding off a few times, but perhaps a food coma from a delicious chicken bake was partly to blame).

IMDb link: http://www.imdb.com/title/tt1182345/