This book was quite entertaining and I would have given it 4-5 stars if it weren't for the ending. The ending seemed rushed and I thought, "is that it?" when I finished it.
It seems like Westerfeld gets to a certain point (I'd say about 3/4 through writing a novel), and he's like "dang, how am I going to end this without adding 200 more pages?" So he just ends it in 20 pages or less. I felt that way about this book and I felt that way about 'Extras'(but I digress...)
Peeps are parasite positive, meaning they are vampires although, they don't tend to use the word vampire. I quite enjoyed the new twist on the same old vampire thing.
I never thought I would say this, but I quite enjoyed all the chapters about parasites. Quite informative and also sort of fun.
I also wanted to mention that this book is quite funny at times. I quite enjoy the humor in this book.