Sam Rockwell is excellent as Sam Bell, a technician sent by himself to supervise some mining on the moon. He plays two versions of Sam Bell. He is a charming, quirky (in a good way), resourceful actor, very physical, very emotionally elastic, and he brings character and intensity to the table. In fact, I am almost certain that he added enormous gravitas to the film. The problem with Moon is that it seems overconcepted but underwritten. Maybe it's a gender thing, but neither I nor my female companion could understand what the hell was going on in terms of narrative.
My first problem is with the notion of a corporation sending someone by himself to the moon for three years. We now know that loneliness is the worst form of torture (as in solitary confinement) and there simply is no reason or explanation why anybody would think it a good idea to send someone to space on his own. Yes, it's a corporation, and we all know what those are capable of; and yes, the guy is in the very soothing company of Kevin Spacey, but still. So we start off having to greatly suspend our disbelief. This is one of the most wonderful paradoxes of movies: you can be watching a fantasy set in planet Bulu, there could be fire spitting dragons and people who walk on their noses, but things still have to happen in a logical, human way. This is why King Kong, for instance, is a masterpiece.
Many of the coherence problems of the film could have been avoided if the writer wasn't so mortally afraid of making certain logical connections or transitions. Sometimes it's important to flesh out the obvious. I also had problems with the emotional logic of the film; I simply did not understand the characters' reactions. Once there are two Sam Bells, one of them decides to pursue the silent treatment. This is utterly flummoxing and extremely uninteresting. Again, I don't know if this is a gender issue but had the film been written by a woman (or by a more experienced screenwriter), the two Sams would be having a gabfest, at the very least. I also was unclear on the motivations of the robot. Is he as evil as Hal? Is he just trained to help? The choices here seem unclear.
The other problem is with the direction. The production design is very good, the special effects (Sam Rockwell arguing with himself) are very well done, but the dramatic staging is shoddy. I wish I could pinpoint exactly why, but I kept having a feeling, particularly at the beginning of the film, that the scenes were kind of messy and unclear. That is, I could feel the lack of chops in the director. I think he has great potential, if he can understand the importance of good writing.
By the way, I forgot to mention one of the highlights of Inglorious Basterds, and that is the music, culled from great film scores by Ennio Morricone, Lalo Schifrin, etc. The music rocks.