I bought this quite by chance, because it was on offer on Amazon and I was intrigued by the synopsys, and I'm so glad I got it. Overall, it's very, very good. Very original world building, and although the storyline comes from a well known trope (Orpheus, anyone ?) it's twisted in very clever ways. I really liked the fact that the heroin was a woman of colour (I may be wrong but I don't think this is so common in fantasy books or even YA in general), which deviated from usual stereotypes associated with the genre. There's also lots of positive aspects in this book, some sentences made me want to do a little victory dance (take that, rape culture !). 
 Obviously, it has flaws, and to me the romance was a major one (just when I thought we'd avoid that stereotype), but the obvious chemistry between the two characters and the way it's written helped a bit. 
 However, even just focusing on the story, it's really thrilling and interesting. I'm not so sure about the sequel (mainly because of the setting and the romance thing...), but I guess we'll see !