I really enjoyed the mystery of the book. However, I feel that there is a delicate balance in mysteries between revealing too much and too little information. The Maze Runner falls on the side of revealing too little information. I know that this is the first book of a trilogy, but the complete lack of information was frustrating as I read. Even when they were revealing information, the story was not truly answering questions, but rather making more of them. It's okay to create more questions, but some of the old should be answered in the process.
I also had problems connecting with any of the characters. The plot moved so quickly that there was never really any time to really get to know the characters, so I didn't care as much about the characters of The Maze Runner as I normally do when I'm reading a story.
If you want a book with a fast-moving plot and a mystery with few answers, this is a good one to try. But if you want a book that is character-driven, this might not be the best book to pick up.