****SPOILERS****
I wanted to give my two cents regarding the film because I had just read the book prior to the movie's release. I wanted to mention that I absolutely love The Martian (movie), and I ended up reading the book after the movie in that case, which is why I picked up the book for PHM (Project Hail Mary) as soon as I saw the trailers for the movie. I really like Andy Weir's writing; it can be kind of numbing when he goes through all the math and equations, but he doesn't do it for very long so it's not overwhelming. He does a pretty good job of dumbing it down so that you understand the gist of the issue at hand.
First, I want to give props to the creators of the movie. Using practical effects instead of CGI as much as possible including making an animatronic out of Rocky was incredible. If you can vote with your wallet that you want to see more of this, please go see the movie. This is the first movie I've seen in theaters in a long time, and it was worth it for sure. The CGI that was used was beautiful.
It might have been just me, but I felt as if the first 1/3 of the film was way too slow (most of it being flashbacks), but the last 2/3 of it went by really fast (while most of this was bad shit that happened on the ship). It might have been because there was no exposition really about why things were happening, it just kind of hurriedly happened. The holes in the two tanks causing the ship to spin out of control was one. Patrick asked why they couldn't just leave the atmosphere of Adrian before pulling up the container, as this was never explained. I do believe the book said that the engines would melt the chain if they tried that.
I was a little weary of Ryan Gosling as Dr. Grace, but he did a good job. I'm just not sure how much was his acting vs the screenplay adaptation. In the book, although Ryland was lighthearted and did crack some jokes, he was a lot smarter than they portrayed on the film; they made him quite a goofball in the movie. Which, you know, I did find funny and I liked it a lot, but I feel as if they dumbed the character down for the film. In the book, none of the other scientists liked him or took him seriously due to the book he wrote about saying that water isn't necessary for life. He explained how much of a disgrace everyone thought he was, which made the impact of him finding out that Astrophage had water in it more... impactful. It also helped when Grace discovered that Astrophage had evolved alongside Eridians and Humans with a progenitor, hence why they all had mitochondria. You could argue that it's pointless to the film but it's a cool thing to note.
They never mentioned the coma gene in the movie, this is also why Grace was picked to replace the dead scientist. Not only did he have the knowledge they needed but also the gene that would allow him to survive a 4-year journey in a coma. There was a huge food issue in the book, because he didn't have enough even with the other two people dead, to survive the 4 years back to Earth. He discovered that he could eat Taumoeba to keep himself alive for the journey, although he'd be extremely malnourished. His memory loss was actually due to Stratt specifically giving him a drug so that he would fail to remember that he didn't want to go, and he was much more pissed in the book once he remembers that.
However, one could argue that none of these things really mattered in the movie, except to add character development. But there is one scene that stood out to me over all others that I wish they would have kept the same: Rocky's "death". In the book, Rocky breaks out of his ball and saves Grace, but then collapses right there. Grace doesn't pass out all the way, and he engages the centrifuge and actually drags Rocky back to his ammonia bubble, which was very difficult because not only was Grace hurt, but Rocky weighed about 400 lbs (they never mention in the movie that Erid also has a much higher gravity along with the ammonia atmosphere). Rocky did not wake up for half a second like he did in the movie, which created a much more definitive viewpoint that he might be dead. This would have been much more impactful to the audience (not that it wasn't already, a couple people told me they cried. Aww). Grace did not get to see Rocky's ship in the book. There was no way to allow his body to survive from the heat/ammonia/gravity. The Xenonite body suit was a completely movie-driven invention. I didn't mind it though, it makes sense to me that the audience would want to see the ship. And it was pretty cool.
The decision to save Rocky instead of going back to Earth was also a bit more involved. Not only would he not have the fuel to do both tasks, but he also knew that he would starve to death. In the book, it is mentioned that Eridians eat rocks/minerals that are toxic to humans, and Erid would not have any food for him to eat or take back home with him. I guess this was never explained in the movie because then they would have to explain how he managed to survive living on Erid. They were able to synthesize meat based on his own muscle tissue. He called them 'me-burgers' lol.
Oh, one last thing that irked me - why would you leave out the best line in the entire book?
“On Earth, we have a scary, deadly creature called a spider. You look like one of those. Just so you know.” “Good. Proud. I am scary space monster. You are leaky space blob.”
It would be like leaving out "I'm gonna have to science the shit out of this" from The Martian movie. Lame.
My main takeaway is that, although I really liked the movie, I feel like I would have liked it a lot more had I not read the book first. And I don't really think it has anything to do with the minor changes they made, per se, but maybe more to do with how I knew how it was going to go. Usually I care not for spoilers, I am more than happy to read all the spoilery stuff so I know what to expect when watching a show or something. But this felt different, I think I just would have liked it more going in without that extra knowledge. Because yeah, the stuff I mentioned is fairly redundant and not needed to advance the story, it's just nice to have it and flesh it out and explain it. The book went into a lot more detail about how Astrophage works, and Rocky's biology etc but I can see how that would just convolute or make the story boring. It's just cool stuff. If you get a chance to read the book, do it. I won't say it's better, but if you want to learn about all the extra stuff, it's a fun read and I enjoyed it a lot. I couldn't put it down most of the time. But also watch the movie, because it's damn good! We need more stuff like this!