This is going to be one of those book reviews wherein I don't feel like I have much to say. It all sort of boils down to this for me: Reading this book feels like watching an anime. Its resemblance to anime is both its strong point and its weakness.
On the plus side this book was very easy for me to visualize, in part because of how much it felt like it was riffing off of anime. There are strong visuals, a world that lifts off the page and comes to life, characters that are instantly recognizable (although they wander into trope-land at times), and plenty of action. It made for a fun fast read. While there were few surprises for me, I did find myself feeling for the characters and caring what happened to them.
The downside is that there isn't a lot of depth to be found. The characters fall into neat familiar categories, their relationship progressions feel more like plot movements than organic evolutions, the environmental angle (which I liked) was heavy handed, and the cultural appropriation was occasionally a bit cringe worthy. To put it another way, beneath the bright colors and shiny coating the bones were on the brittle side and don't stand up to intense scrutiny or pressure.
All of that said, to the best of my knowledge this is Kristoff's first published novel, and for a debut it holds up decently well. I liked the story and the characters enough that I'm planning on reading the rest of the series and seeing where the story goes, as well as how his writing chops improve. (I've read Illuminae and it was fantastic.) If a fast paced anime-esque romp through a not-quite-Japan steampunk fantasy setting sounds like fun to you give this one a try, just don't expect anything too deep or nuanced.