I was also really disappointed by the adaptation, especially compared to the Martian. I'll see if I can find the comment where I talked about why and I'll come back and copy paste it.

Edit: here it is:

NOTE: I've tried to keep this as spoiler-free as possible, but even so you may not want to read this until after you've seen the movie.

The movie was definitely good, but fell pretty short compared to the book, and especially when compared to The Martian's adaptation.

For one, the movie felt way too much like a comedy, almost like a Taika Waititi Marvel adaptation of the much more serious (but still very funny) book, which felt tonally weird and didn't really land for me. Even the weight of the reveal of

was completely undercut by a tonally inappropriate, almost zany

that robbed the scene of most of the pathos it should have had. Reminds me of this excellent video about how modern blockbusters seem allergic to sincerity to their detriment.

We also didn't like how much more useless the movie made Grace feel. The book went out of its way early to show that he was a resourceful, intelligent, excellent problem solver, and while there was certainly a bit of this in the movie, it still felt like Grace was pretty much useless, undeserving dead weight, and like he either completely lucked his way through or had to rely only on

while in the book their partnership felt much more collaborative. All of this combined to make the reveal I mentioned earlier feel much darker/more depressing, because you get the impression that no, he really didn't deserve to be there, and then what he says at the end of the movie completely falls flat, because it felt like almost none of it was the result of his choices or character. Feels like it completely undercuts one of the main themes of the book, which is that he did deserve to be there, and that he was the right person for the job, even if he didn't think he was.

We also thought the movie omitted some of the book's best lines. "You can hear light?" is an all-time great line that still gives me shivers, and it definitely should have been in the movie.

Things we liked: 1. The movie was visually stunning - everything it was going for in the looks department it completely nailed. 2. One of the most important characters in the movie was very well done, in both design and characterization. Maybe a bit too manic, but that's a relatively small quibble in the larger context of just how well they did with him.

So yeah, very much an enjoyable two hours, but not as good as it should have been due to a few flawed adaptation decisions.

Such an interesting premise ruined by fourth-grade humor. I don't mind having some dry humor moments, but it was the entire freakin' thing.

The book was MUCH better. I think it was made assuming most its audience read the book.

I would never put the book as a comedy. Was the movie supposed to be funny?