There is a reason why I don't read YA books. Forgive me - this might get long. 
 The Good: 
 I have such conflicted feelings toward this book, so let me get all of the good out first. 
 The idea of Oz being ruled by an evil Dorothy is captivating. Really, the idea is pretty genius. And the author was able to create a separate world different from the movie-Oz or play-Oz that was easy to picture without being warped by preconceived images. The imagery itself was incredible. The author has some serious chops when it comes to describing places so unlike what we're used to. 
 I liked how nothing was sugarcoated. When something (or someone) was mangled, it was described frankly. When people were being hurt, it was descriptive, but not overly-gory. That being said, there were a few times I was legitimately scared because something was that dang scary. Even reading The Shining hasn't had me that scared. 
 As for the characters, Amy was okay. But only just. Everybody else was kinda there, kinda not. It was definitely all about Amy, so if you dislike books centered around one POV, that was hard to get used to. Still, as Amy is a teenager, I think she was written well from that standpoint. 
 The Bad: 
 Like I said, I don't read YA books, but this was one I couldn't not read. Everything cliche about YA novels was in this book: heroine with a tragic backstory; heroine with snarky attitude; heroine supposedly being the "only one" who could do something (though that's never explained at all - surprise.); the dreaded love-triangle. The list goes on. 
 I think one of the reasons I became so upset as I read this book was because it had such potential to be different from the rest of the YA genre. But when Amy became too much like Katniss and when it kinda set itself up for Team Pete or Team Nox, I was disappointed. The majority of the novel is spent listening to Amy whine about her mother, whine about her life in Kansas, and whine because she has no idea why she's doing what she's doing. The book would have been 10x better had Amy either been older or told in third person. Then the story would have been focused on the mission. Not Amy's feelings toward Nox or her crappy life. 
 Content: 
 Language: Moderate (frequent usage of d--m, b-tch, sh-t; one f-word) 
 Religion: None 
 Romance: Clean 
 Violence: Heavy (some very disturbing images)