I’m going to start off by saying I’ve not (yet) read the book, which makes me probably the only person not comparing the two.
So, the synopsis: Mark Watney is collecting dirt on Mars as part of one of the first manned missions to the planet. Cue big dust storm, tragic accident, and Watney is abandoned alone on the planet with no hope of rescue. The rest of the movie involves a series of problems of survival and rescue.
The Martian tackles the monumental job of adapting conflicts that involve high level of scientific jargon to the big screen. As is usually the case, this involves a series of “let me explain this to you” speeches. They’re staples of Star Trek and CSI. Especially the latter involved a geeky lab assistant explaining high school chemistry or biology yet again to other professionals on a weekly basis.
In contrast, the exposition in The Martian makes a bit of sense. Half of it comes through Watney’s video log of his self-engineered survival. Half of it comes from the fact that big science is big, involving teams of hundreds of highly specialized experts. A good chunk of action on Earth involves getting the right people in a conversation with each other to explain the next conflict.
Probably because of this, the dramatics of a man struggling to survive in nearly complete isolation are understated. Show don’t tell is probably good thing for a movie that requires so much telling up front. The movie does a reasonably good job of balancing among exposition, tense decision scenes, and action sequences/montages. A fair number of things go bang and boom, which helps the pacing never feel like it’s one long science lecture.
I think one of the beautiful things about The Martian is that it’s an action movie about smart people being smart. This is a distinct contrast to Marvel offerings which seem to be primarily smart people acting with spectacular stupidity. The Martian manages to milk action out of concepts like relative velocity, minimal calories, and hexadecimal notation.
Where it falls a little bit short for me is that The Martian isn’t very introspective and doesn’t wrestle with big ideas beyond NASA and JPL’s ability to make things work. This struck me as better than Age of Ultron, which used at least a half-dozen different big ideas as scenic decor. (Fury Road, in contrast, felt like a movie that might have read Tepper or Butler.) But that’s a small complaint for a $5.75 matinee.