First of all, I have to say that I hate this book's cover. The illustration doesn't match the character descriptions, and I almost didn't read the book simply because the cover. (I generally ignore the saying "You can't judge a book by its cover.")
However, this saying proved true with Under the Never Sky. While the beginning is definitely confusing--you don't receive explanations of the world for a while--the characters and world Rossi creates are phenomenal. I didn't guess any of the plot surprises (except one, which the cover gives away), which made me want to keep reading all the more.
Overall, don't let the cover deter you from reading. It's well worth it.