Factual error: When a person goes out into space, their eyes wouldn't be sucked out, their cheeks puffed, etc. They would have about 10-20 seconds of useful consciousness, when they could get back to a safe area. Even after that, they'd still be alive for about a minute, although unconscious. The only major problem that being in space for about half a minute might cause is rupturing the eardrums and possible blindness (although the eyeballs wouldn't be graphically sucked out). NASA's studies on this go back as far as the 1960's and were used by Stanley Kubrick during the making of 2001: A Space Odyssey. (00:03:50 - 01:43:20)
Factual error: Martian sky is very inaccurate in the movie. It is depicted as much darker and redder than it would be in real life (Mars' sky is a butterscotch color during daytime, bluish at sunrise/sunset and far brighter than in the movie). Also, both of Mars' moons are very small, asteroid-like bodies and would appear as tinny star-like points of light to an observer on the surface of the planet.