This was probably the most disappointed I've ever been after reading a book or series. It had so much potential and I had very high expectations, which is probably part of the reason I was unprepared for it to be so lackluster. The idea was very interesting and enveloping, but it absolutely just never went anywhere with it. Honestly, I'm glad I read it because it made me excited for the movie adaptation, which I must say is one of the few cases where the movie is way better than the book.
The first book drew me in hard. I was scared and nervous and excited, and I had crazy dreams both nights after reading it. The second book was the hardest time I've ever had making it through a book and it was for nothing. It could have been one chapter in the third book to introduce some characters. I was expecting closure in the third book that painfully never came. It was like getting pushed off of a cliff, but the cliff keeps moving away from you. At some point, the adrenaline of being on the edge goes away, and you just want it to come to an end. I'm very stubborn when it comes to books, and I make every effort to finish what I start. So that is why I got through the series, even though it was rough.
I have a very hard time giving even mildly critical reviews, because I really appreciate the author's creativity. I couldn't write a book half this good, but I was crushed by not having any semblance of closure. I've read books with endings that are up for interpretation, but this is something entirely different.
Like I said, I really enjoyed the movie. It is loosely based on a manuscript of the first book prior to its release. For this reason, I think it's a good idea to read the first book so that you are aware of what is going on. Reading the whole series is not necessary, although in the movie, I feel like I noticed some very small things from the second or third books. They may have been in the manuscript, but got pushed to the following books.
This series is not for everyone. It is definitely unique and interesting, but it takes real dedication to get through it and with little reward. My suggestion is to read the first one (get it when it's on sale), and see how you feel. If you find it very intriguing, you could give the others a try, but definitely be aware that you will know barely anything more at the end of the series than you do at the end of the first book. Good luck.