Authentic sci-fi, always appreciated. +1 on that alone. Good movie regardless.
I did not watch any trailers or read anything beyond a minimalist blurb about this movie, so I went in with no preconceptions. I caught on to the basic premise very quickly. The rules seem to originate from established sci-fi, which made it all the more enjoyable to me.
Gerty is a robot, so advanced it may be sentient, like Hal. But unlike Hal, it was created by smarter humans who probably read Isaac Asimov. The 3 laws of robotics emerged not from benevolence, but from a desire to prevent a future such as Cyberdyne (Terminator movies). These 3 laws are at the very core of a sentient-robot's thought processes, and can never be bypassed without destroying its intelligence. It cannot harm a human being, or through inaction allow a human being to come to harm (first law).
Gerty may have been instructed to protect the big, evil corporation's business, but the deeper directive to protect humans overrode it when there was a conflict (2nd law). Everything it did was consistent with this boilerplate.
The concepts of mining the moon, and cloning with possible inherent flaws in each copy take the setting the rest of the way.
Good story, without falling prey to some Hollywood money guy screwing it up with mindless action or horror elements to draw in the popcorn masses.