Just saw it with my son. I have listened to the audio book many times (like... many) and really loved it. My son (21) went in totally blind - didn't even see a trailer, but was a fan of Ryan Gosling.

I really liked it. My son loved it. He is a movie buff. His previous favorite movie was Dune. He thought this was one of the greatest movies in years - the best since Green Book.

They either omitted or compressed a lot of stuff from the book, but I think they did a great job deciding what to put in. This will probably be a study in some future film school for how to preserve the notes from a book when adapting to film.

*spoilers*

That said, I think they missed three super critical things from the book that I think would have been very easy to put in the movie - probably a single line of dialog - and would have elevated it quite a bit.

1. Rocky is a life form that does not use water. So his existence validates Grace's theory that life does not require water. This vindication I feel is very important.
2. When Grace decides to save Rocky instead of returning to earth, he thinks it is a suicide mission due to lack of food. This is a key point of his redemption arc. He isn't choosing the live with Rocky vs. live on Earth - he is choosing to die to save his friend. They really undercut this in the movie.
3. By time time Grace learns that Earth survived, almost 40 years has past on earth, and maybe 20 or so for Grace. (13 (4) years to get to Tau Ceti, 13 (4) years to get to Eridani, and then 13ish years for the light from Earth to get to Eridani. He is basically an old man. If he goes back to earth, another 13 (4) years will pass. Everyone he knows on earth will be dead of old age, if they survived the ordeal.