I thought this was a good film, an interesting SF film, and it's pleasant to see an SF film that doesn't insult your intelligence. The story will work for people whose standards are set by written SF. I don't think it's a film that in years to come you will think 'Oh, why didn't I go see it?' or one that fills you with that sense of cosmic excitement and sublimity. But I liked it, I like Sam Rockwell, and I like any actor who takes a part seriously without being all 'I'm an actor' about it. The emotion you are left with is compassion.
This reminded me a lot of a similar small-scale SF film from the early eighties, Android, starring Klaus Kinski and Don Keith Opper as an innocent young fellow stuck on a space station (though as the name would imply, with a different premise). That's worth checking out if you get the chance some time.