One fact is established as certain— this is a utopia gone wrong.
What I liked best about the main character, Kelsea, is her appreciation for books. She offers some diversity in that she is plain looking and overweight. Skin shades were also mentioned a few times, mostly in that dark skin was rare in this world.
I was very impressed with the rich vocabulary that Harper publishing permitted the book to use. There was a whole host of words rarely seen printed in fiction nowadays.
The climax felt reminiscent of Breaking Dawn (Stephenie Meyer's Twilight saga) in that the main character finally reaches the eluded-to powerful self, but the battle fizzles. If tension is about "how can this main character defeat that enemy," there's a disappointment here. It does, however, "sell the next book," in that now the story is developed. It feels less like the first book in a series and more like an origin story that has to read, or got out of the way, in order to get to the action.
Despite that, the book leaves a great deal of background questions. The biggest being where The Tearling (and other countries) actually are located. It seems to take place in a future where most technology and advancements have been lost— some intentionally.
The main religion is a mix of Catholic, Protestant, and preservation of the species. Readers who are easily upset by atheist may be offended by this work of fiction. Also note that there are adult situations and language in this story.