I don't think more than one or two onboard have seen Moon, but I wanted to get these spoiler discussions down while my impressions are still fresh. The DVD will likely be out by the holidays.

Basically, I agree with the critical consensus that his is a gem, a true classic, and an amazing piece of old-school, pre-CGI, story- and performance-driven film art. If it doesn't garner an Oscar nomination or two, it will be a crime. (Best Actor, at least. Contender for Screenplay. Maybe Editing.)

But it has some... flaws. Let's discuss.

1) As Dan pointed out, there is no attempt to replicate lunar gravity in most scenes. The exterior sequence are as faithful as practical sets and every filmic trick in the book except CGI can make them. But the interior shots - not even a sop to low gravity. Okay, has to be excused for budgetary reasons and never really affects the story.

2) The bit with the signal jammers is total McGuffin. If they need to isolate the base from outside contact, it seems like it could be done with a simple switch somewhere or the programming of the hardware. Giving Sam fully functional comm equipment (and, probably, complete training in its use and repair) and then setting up enormous jammers all around him is just... stupid. If GERTY can turn them off (apparently), then they make even less sense. It seems like they are set up entirely to provide a gosh-wow-what's-that? moment in the film and a more dramatic event at the end. But the absurdity bothered me once I realized what was going on. Giving Sam less training or understanding, or putting in foolproof cutouts under GERTY's control (which apparently exist but are not explained), would be more sensible.

3) In the end, there's absolutely no reason for the base to be manned. Sam does nothing but sit around in case there is an anomaly - and since one harvester is mysteriously out of action for the whole film, he clearly can't do much - and move the energy capsules from the harvesters to the launching pod. The latter would be well within the capacity of an automated, AI-driven system. Since some sort of rescue/repair/fix-it team is only a few hours away, there's no need to maintain a human presence at the base.

4) If there's no need for a human, there's no need for the... extremely complex support system portrayed in the film.

5) The ending - the last minute - could go any way at all. I can think of four or five perfectly seamless, logical endings from the time Sam hits the launch button. The one chosen seems excessively... happy happy. As tired as I am of films with grim, dirty, depressing endings, and as much as they might have had to cram a complex ending into a few minutes, I think a more satisfying ending could have been crafted.

The film also has one aspect that some viewers may overlook. For a time, we don't know what's going on with... the other person. Is Sam just nuts and hallucinating? Is it some kind of nasty trick by the company? We don't know, and the clues are ambiguous.

The director does something brilliant with this. Watch the duo scenes carefully as the film progresses. Early on, the two characters never touch, never get close to each other - something that could be done with the simplest matte technology. It sets up a notion like A Beautiful Mind, Fight Club or Sixth Sense , where the second person turns out to be the figment of the viewpoint actor's imagination, or otherwise "not there." You never notice that the second person never moves an object, touches the actor, etc. but it sets up a distance, a "something's wrong here" perception.

Then the director starts to yank the chain. The interaction gets closer, and closer, and more involved, and the notions of a simple matte dissolve in scenes where the two characters struggle, knock things over, and even tussle over objects like the ping-pong paddle. They start crossing into each other's territory and all of a sudden you're scratching your head and rethinking both the film process and the story. Holy smokes, the second guy is REAL! Beautifully and subtly done, and one reason I think an Editing Oscar might be in the cards.

This came up in my Netflix so you can get it on Blueray. I liked it OK, but the science was terrible not only the gravity issues most people noticed (the treadmill should have put him through the wall). The outside scenes were just all wrong.
I did like the launch tubes, can we say catapult?

My wife gets upset because I tend to pick on the technology in movies, even when I enjoy them. Anyway the outside shots are what you would see on earth outside well away from lights. You would not see all those stars in the sky (going from what pictures I have seen taken on the moon). A real nit: I don’t think they could simulate at all, but shadows would appear completely black.
Yes they have designed exercise equipment for space missions, but they do not look anything like what you would see on earth
I agree, when you really think about it; if they are that good with robots you would not need a human in the station at all.

One striking thing about this movie was the utterly relentless use of on all signs, control panels, vehicles, etc.

I didn't spot anyplace where a different font appeared. I guess this supports the Sixties-SF aesthetic of the film.