Frankly, I didn't like the book at all. Certainly it is well written (in the sense of literary style) but the plot is flat. At no time was I hooked by the story, no suspense. And even if the end redeems the beginning a little, this book is clearly not interesting to read.
Very good game, new worlds, great music (It has always been the case of Kingdom Hearts you tell me), a lot of really nice gameplay novelties, a good life if you want to make all the worlds to 100%, explore everything, and get all the trophies, and life remaining a lot if you want to do the game in a straight line (about 25h) which I advise against all the same so much the worlds of the game are great and abundant contents to pick up.