Compulsively reading and entertaining. Interesting science. A little bit emotionally affecting near the end. Sooo Martian-like. (And I liked The Martian, so that's not entirely bad.)

Weakest when Weir went out of his way to have one facet of Grace's personality not be Mark Watney. Like practically had a neon sign over Grace's bed saying "I'm not Mark". One could spin the big attitude difference as being "character development" or a "redemption arc", but it felt really shoehorned in to me, and made the book a little less, in my opinion.

Still, if The Martian is the sort of thing you like, you'll probably really enjoy this too. Might as well read it before it's a movie.