So this contains spoilers in case anyone's waiting until the very last minute to watch the movie, but there was just something that I found very interesting about Moon that I thought would be interesting to discuss here.
From the minute the movie started and we were introduced to the Kevin Spacey-voiced GERTY, I was SURE that GERTY was going to ultimately be the villain of the piece. It seems to me, that whenever there is a 'character' like GERTY in sci fi works, such as HAL from 2001: A Space Odyssey and the chimp in The Island, they end up being quite villainous in some way. So I was quite surprised when GERTY actually helped the 'Sam's. I thought it was really interesting way to take the usual 'robots are bad' technique and flip it. In this case, the humans on Earth seemed much scarier than GERTY, who was only programmed to help Sam and all of his later clones however it could. I just thought it was very clever of Duncan Jones (original story writer and director).