Not sure what to think about this one so no rating. I'm not recommending for or against.
The elements were there. I liked the writing style. It wasn't the same old insta-lust fated mate crap some urban fantasy -- which genre maybe this was or wasn't since mostly in a parallel dimension -- substitutes for story.
The ebook I borrowed via library was actually hard to read so could factor into that. Too many words strung together without spaces kept interrupting my reading flow and slowing me down. Which isn't the fault of the story itself.
I certainly should have been invested in the desparate straits of that world's humans versus invading demons. That part kept drawing me in to read more. But, I never really connected and it never really developed the way I needed -- maybe a little because of the lustful interludes but mostly because the worldbuilding elements and the invading aliens had glimpses of a richer story. A richer story that possibly reading further in the series would develop. This would not be the first series I could enjoy once over the first-book-itis.
The romance -- while progressing at a good pace and understandable why the interest -- kept wavering on whether it wanted to edge into some of the worst elements of the fated-mate-possessive stuff where perversely I started to wish it would rather than read the lusty bits where the H and h seemed to draw some pretty arbitrary do/don't and is/isn't-taking advantage rules. Again, made me not really connect to characters that should have drawn me in.
I dunno. This clearly is not a good review of the book because I'm not sure how I feel about it or what to say.