This was lovingly written by an obvious space nerd. Weir explains large amounts of science and engineering in a very accessible format. As only a true space nerd would do, there are lots of jokes and puns. Not everyone will like them, but they enhanced the story for me.
The story works as a framework to describe the technical challenges to life on Mars. The Apollo missions were visits of a few short days and Whatney, our hero, was planned to have a few short weeks on Mars. Only it goes all wrong.
What I enjoyed most was
the isolation. So many authors try but fall flat.
Given the fiction part of science-fiction, the problems arrive one after another to give Whatney something to solve without too much of a break to recover. A normal mortal would have broken under the stress. But, then, NASA would not send a normal mortal to Mars. 🙂