I'm just gonna warn you ahead of time, I'm gonna spoil this movie in the review.

The reason why being that, while a lot of other blogs and critics opt to take the route of saying that "they can't go into too much detail" because the plot, in itself, is a spoiler, I believe that it makes it a lot easier to praise by spoiling a little bit and giving you the option of whether or not you'd like to read it.

Thus, I'll mark spoilers in their own little section.

But basically, the movie is about Sam Bell (Sam Rockwell), an astronaut on a three-year lunar mining contract. He's scheduled to go back home in two weeks. He works for an energy company called Lunar Industries that specializes in mining a chemical on the far side of the moon known as Helium 3, supposedly the cleanest source of global energy yet discovered.

Bell has a wife and daughter, from whom, by taking the mining contract, he's been separated for the last three years. His wife sends him frequent video messages telling him she misses him and that she thinks the separation was a good thing for both of them (they supposedly had problems). The lunar live communications satellite is broken, and thus intermittent pre-recorded messages are his only link to the outside world.

His only friend is the lunar base's computer, Gerty (voiced by Kevin Spacey), a polite, monotone helper whose feelings are expressed by a screen displaying emoticons. Unlike "2001's" HAL 9000, Gerty is programmed to protect the man, not the mission, which makes him a more blatant opposite to HAL later in the film.

(BEGIN SPOILERS)

One day, Bell suits up and goes out in a Moon Rover to collect a deposit of H3 from one of the unmanned mining vehicles on the Moon's surface. On his way there, he sees, amidst a hail of rocks being spewed from a vent on the top of the miner, the ghostly, elusive silhouette of a young woman on the surface (and when I say elusive, I mean it. I had to squint). While distracted, the rover crashes and he is knocked unconscious.

Some time later, Bell wakes up in the base's infirmary, suddenly looking younger and more in shape than he did previously. When asking where he is, Gerty tells him that he's suffered from an accident and that he'll need to stay put.

Bell goes through a number of physical and psychological tests, which he eventually decides he's had enough of when he discovers that one of the mining vehicles, the same one that he crashed into, has gone offline. He's told that he can't leave the base, and being the clever man that he is, decides to start a gas leak to make Gerty let him leave the base to "check to see if there's any damage outside."

On his way out, he discovers one of the atmospheric suits is missing.

He gets in another rover and drives out to the crash site, where he finds the crashed rover as it was before. He opens up the hatch, and, surprise surprise, finds himself, unconscious and bloody.

(END SPOILERS)

The sad thing about this movie is that all of what I've just told you can be seen in the trailer. I won't go into further detail, as there is a background to Bell's discovery, but it's a slippery slope of developments, and the big twists all take place early on in the movie.

What I can tell you, however, and what you should see the movie for whether or not you know what happens, is that Sam Rockwell is awe-inspiring in this performance. Not only is he playing two versions of himself, but he's playing essentially two completely different people that are kept together by the fact that they are physically and, at the core, the same person.

But the movie is flawed, luckily in a way that you can ignore if you keep your eyes on Rockwell the entire time, which isn't difficult. However, there are plot developments that are unexplained, a narrative that can't quite decide what its scope is, and an ending that could have been so much better.

Also, as an aside, I kept getting the feeling that this movie could have been just as good or even better with Mark Ruffalo in the lead role. I don't really have any strong reasoning for saying that, I'm just pointing that out. The guy's great. Give him some work like this.

Fortunately, the movie is a visual powerhouse, which one would expect from first-time director Duncan Jones, who is the son of none other than David Bowie himself. The guy has created a strong first effort that shows a lot of promise, but doesn't quite deliver on all the levels that I expected it to.

But that's all beside the point. The movie has enough to keep you captivated the entire first time you watch it, with a stunning lead performance and an appropriately modest pace. I give it an A-.