I would have given this book a 5 star if I only read to the middle of it. The suspense and build-up of the plot were very good in the first half of the book. It was truly a page-turner. The science idea was new to me that keep my curiosity going.
But the second half seems like it is running out of idea and not sure where to turn to. Eventually, it leads to a not so satisfying ending. The situation is similar to the TV drama “Lost” that the build-up at the beginning was too amazing and mysterious that needs an even greater ending to fill up the expectation. And it is so easy to cause disappointment. Another point I noticed is that there should be more details on the science behind the virtual world to make it real to the reader. For example, the dry-up human being for preservation during the “bad weather” sounds like some sort of jokes because there was no “make-up science” to back it up. It should have been really good science fiction for me should the above are fulfilled.