Sam Bell (Sam Rockwell) is almost home. He's spent nearly three years mining helium-3 from the dark side of the moon and he's just two weeks shy of finally seeing his wife and daughter up close rather than onscreen. Nothing against helpful robot Gerty (voiced by Kevin Spacey), but Sam could use some real company. That is, until an incident crops up that grants his desire for guests, but puts him farther away from home than he ever imagined.
Those looking to venture into Duncan Jones' Moon unspoiled would do well to avoid the remainder of this paragraph, although Jones himself has confirmed that the key development in the first reel is the thrust of the narrative and not just some twist. (Although there is value in going in blind, the reveal does not harm the experience as a whole.) Ready? As it turns out, Sam is not alone because he's not the only Sam Bell. That three-year contract of his is actually the lifespan for clones like him, who toil away for a corporate entity that only sees their strategy as a model of efficiency.
That development is what ranks Rockwell's work here among the year's most uniquely layered acting efforts, a sometimes-simultaneous showcase of one man's many sides that surely would've collapsed into gimmickry and hysterics in anyone else's hands. Whether playing ill-tempered or falling ill, regressive or aggressive, Rockwell makes the most of the given conflict, and it may come to stand as the defining performance in the character actor's career.
Gerty's knack for using smiley and frowny faces when trying to reason or banter with Sam, combined with Spacey's monotonous voice work, transforms him from the requisite robot to an anthropomorphically satisfying foil, a kindred spirit as a fellow tool of the future (if more in purpose than in personality).
Jones, the son of David Bowie, isn't shy in his directorial debut about trying to twist other sci-fi staples, employing model effects rather than CGI and indebting himself most heavily to the genre's heyday of ideas over camera tricks ' big ideas on a small scale. One might imagine his Sam Bell hitting it off quite well with Silent Running's plant-fond protagonist, and Gerty's 3000 model could very well make him a distant relative of 2001's HAL 9000.
The pensive mood is helped immensely by the ethereal contributions of composer Clint Mansell (The Fountain). Though Jones tries to alleviate that mood with the occasional bit of humor (a coy song choice here, a one-motto-fits-all T-shirt there), he strikes a proper tone considering the conflicts he and Rockwell are working with. They're contemplating a future full of potential and yet robbed of hope, an era where the worst malfunction technology can suffer is to function too well for its own good; in this way, Moon both takes off and hits home.