...let's try this whole "write a book response right after you finish it instead of agonizing over things and putting them off" strategy.
Can I start off by saying it will never stop feeling weird to finish a book and unexpectedly see a Dreamwidth friend thanked in the acknowledgements (even if I know the author is also active on DW?) The fact that it happens a couple of times a year lately and the first time it was my sister just makes it weirder, tbh. Posting a review suddenly feels a lot more like trying to post fanfic crit, even though I know it's a completely different context.
Anyway, about this book: it was a super fun book! The worldbuilding was amazing and the way the science fiction and mythology worked together was seamless, and it was exactly the kind of space adventure that I want my space adventure to be.
It did feel kind of like someone had come up to a really good writer of epic adult SF and handed him a Formula For Writing A Junior-Grade Novel and he very carefully ticked off all of those things. Which, to be fair, is probably more-or-less what happened! I had somehow filed it in my head as Y rather than J (even though it wasn't), and I've read some Machineries of Empire short fiction (brilliant and amazing) so I think I was just expecting something different in terms of the formula. I think of myself as someone who actually reads, and enjoys, a fair amount of junior grade fiction? But now that I think about it, nearly all of it I've read recently falls more-or-less into the very specific categories of a) very old books (where 'books from my childhood' already count as very old...), b) absurdist/satiric humor, and c) comics, and in all of those, the JG-formula elements work differently than in something that is just trying to be a very good SF story that follows them.
This did give me some motivation to try to rework a couple of my SF story ideas that wanted to be Y-fic into junior grade instead and seeing what happens, though!
The other thing that bothered me a little bit was that ( thematic spoilers, I guess )
I am probably going to bump Machineries of Empire forward on my to-read list (which was kind of the idea behind trying this one first.) Because!! Now that I've finished this, I've read all my library books for the first time in I don't know how long! (Okay I haven't finished Romance of the Three Kingdoms but I checked that out intending it to take forever.) It feels weird and freeing. Probably I should go read that pile of FMKs I'm still putting off, but what I will probably do is get out all the Hugo and Lodestar nominees I haven't read yet instead and then get way behind again. :P
Also I was reading this in public and somebody thought it was Dragon of the Lost Sea based on the title, so I got to have a random conversation about my old favorite queer-as-hell junior grade series about a missing terraforming tool based heavily on an Eastern mythology, which was a great bonus. Crossover time! :D