Great watch, would watch again, and do recommend.
Sam Rockwell no only carries the movie, but he's literally the only person in the movie that isn't on a screen.
He plays off himself amazingly well and really balances the struggles of both the individual and the clone to clone interaction. The struggle feels like how someone would react to the situation, and Rockwell adds his own special flair to it.
The setting of Luna is amazing, granted it's mostly in the small station, but it makes me jealous that we haven't established moon colonies. Space madness might be a real thing, but it is because someone is alone and not part of a group.
I want more movies like this for every reason: more Sam Rockwell, more Luna settings, more clone movies, more isolation theory, more, "OMG, MY ENTIRE LIFE IS A LIE, WHAT IS HAPPENING!".