I found this book took a little while to get into because the world building was quite complicated. Once I was into it I enjoyed the middle section very much. the character development and plot flowed along nicely. I particularly liked the characters of Simon and Isabelle, and the sarcasm and great one-liners had me laughing out loud. 
 Some of the features of this world seemed to be a conglomeration of many other YA fantasies I've read - werewolves, vampires, humans referred to as mundanes. But then, isn't everyone influenced by what they've read? The end product was still pretty original, as was the make up of the world. I found it difficult to follow how the rune magic worked, though. 
 I didn't really like the ending. There was a big "ew" moment. If you've read it, you'll know what I mean, so I won't spoil the surprise. It was an interesting turn of events, and a good set up for future books, whilst giving a certain amount of closure. 
 I haven't yet decided whether I will read more books in the series. So many books, so little time ...