I don't know what else I can add to all the positive and accurate praises about this book. I've seen even non-SciFi fans making this, one of their favorite books of all time. It's "Good, good, good!!"
Sure it's a thick boi, but there was not a page that made me bored. Some people may complain a bit about the too science-y parts but I think Andy Weir wrote the technical parts so inviting, weiving it nicely into the plot pieces that he makes you think you understand it completely.
It is very well-structured, uplifting, and so so fun! Also, I cannot think of a better ending for Ryland Grace's space hero adventure. I love it!