I agree, Red Planet was a better movie with a better story, and although I can pick out all its mistakes, I think they tried a little harder to make the science believable.
Why do I hear that all the time? Personally, I liked the movie. Sure, it's not particularly plausible, but it was a cool movie. Besides, how many flicks do you find Story Musgrave in? lol
BTW, the addon is fairly crap. I downloaded it because my son likes the film, but it is really not very much like the movie ship at all. It looks a bit messed up, to be honest. Besides, I don't think there's any way of getting to the surface with it. And it doesn't have Gary Sinise in it.