I described it recently as a space heist. That is not perfectly accurate because it lands closer to sabotage than a classic heist, but the energy is similar. It is very much an underdog story about someone trying to climb out of the hole they are in and being willing to take risks to do it.
It is probably the most straightforwardly fun of Andy Weir's books for me, and it still carries the same readable style that makes his work easy to recommend. He has yet to disappoint.