Economical in its minimal use of exposition employed to excess in too many Sci-Fi pictures, MOON is also unpredictable, eerie and somewhat impersonal throughout. Although it is certainly a burden for any performer to carry an entire movie, Sam Rockwell's is not a role that requires much beyond serviceability, standard equipment of any good actor that I see him to be. By the way, It was a true surpise that Gertie (as voiced by Kevin Spacey) did not turn out to be a malevolent piece of machinery like that of a particular SF movie of 41 years ago. Overall, I thought this to a distinguished film despite having a conventional ending.