Moon is a suspense set on a moonbase and starring Sam Rockwell; and when I say 'starring' this is more than usual since he's almost the entire cast, having no one but himself to play off for most of the movie, apart from a computer's disembodied voice (played by Kevin Spacey) and a few video clips of other people now and then. I'm very impressed with his acting, and his ability to carry off a very complicated role single-handedly.
The movie had excellent production values, and the science depicted in it was solid; it deviated from what we know to be possible only in the minimum ways necessary to make the story happen, and didn't focus on them, since they weren't what the story was about.
The story was layered with puzzles and mysteries, and from the start, we're led to thinking that we know what the question is, and maybe have a guess about the answer, only to find out that what we thought might be dragged out for the entire movie was only part of the story, part of the mystery. Thus we're spared the annoying consequence of wondering why the characters (or character) in the movie can't figure out what we can. This also ensured we kept having things to figure out for the entire run of the show.
The rest of my review will involve spoilers and I highly recommend avoiding them if you haven't seen the movie. From here, I'll just conclude: this is a great suspense/thriller and well worth a watch. And Sam Rockwell once again is a marvel.
I had just one problem with the movie's story, though. There was one small deus ex machina that really couldn't be justified. It doesn't make the slightest bit of sense that the He3 return system could bring back a person. One little throwaway line about how he did the calculations and there'd be some heavy Gs wasn't enough to explain it. Why would anyone build something designed to return compressed He3 so that it could come anywhere near being able to sustain a human life? Even if the forces weren't crushing, and even if his suit can do life support for three days, the temperature gradients on reentry would almost certainly be unconducive to life. The return module probably doesn't come down next to a hotel, either; it probably goes into a remote processing plant that, given how the rest of the company works, is entirely automated and thus devoid of people.
A few lines earlier in the movie to establish something about the return system could have eased this, but I really wondered if the story was going to go another way (the Eliza clearly was a possible way home, for instance). This is a quibble, admittedly; in most movies this wouldn't even make a dent, but this movie holds itself to a much stricter standard so this small failing weighs heavily.