This book had so many exciting ideas that I wish had been explored more in-depth than they were.
Ruinsong has one of the most unique magic systems I have encountered in a fantasy novel. I wanted to know so much more about the different branches of magic that exist. While this is such an integral part of the story, this was brushed over,

Cadence is... remarkably uninteresting as a character to follow; her motivations are entirely self-centered. She commits acts that are very much war crimes, and this book does not address it.
Cadence as a character is the exemplary example of the discussion of if someone turned a blind eye to the things happening in Germany during WW2, can we really say they weren't a Nazi? Especially with Cadence being in such a high position of power.
There are undertones of the argument of how she was raised, and because she was never taught how to defend herself, how could she possibly fight this higher power.

Spoiler

In reality, Cadence doesn't seek out the need to learn how she can help; she is pressured into it and is pressured into everything she does to counter the Queen.
In the end, Cadence doesn't answer to any of the above; the book kind of shrugs and is like, well, she gets pardoned by her GF's mom, and everything is just hunky-dory.

What I will sing praises for is the queer representation, alongside the representation of non-monogamous relationships. Non-monogamy is rarely shown in books as an option, which is the biggest annoyance when it comes to Love Triangles because I'm like, WHY NOT BOTH?
But to read a story where it is 'mostly' normal to have queer and non-monogamous relationships and straight monogamy isn't the default was incredibly refreshing. Even if it also features insta-love.

All in All:
I would recommend this book to anyone looking for an interesting read with a nice side of romance. But isn't wanting to think too deeply about things going on in the book,
But don't expect it to follow through on:
Her voice was her prison…
Now it’s her weapon.