If you're not sure whether to watch this. Watch it! I was in a half mind to because I don't always trust ratings (especially for modern movies) and I'm usually dissapointed, however, this was really good.
Basically, its about a lunar drilling company operating illegal practices, but in an interesting sci-fi setting. I liked the mystery and the story. Rockwell was great and had room to shine, with a few interesting reactions that could have been terrible but made the character and sertting more interesting. Spacey was perfect for the robot. One or two sadder moments in the movie that worked.
The music is by Clint Mansell. I'm not a massive fan. I like his work but it seems to lack something. The music seemed overused but it's doesn't effect the movie. The effects are a little below average at times.