It's a good book, kinda. If your a kid you might find this book interesting an fun to read but to me it's not so good and I'm only 14. First of all, The theme in this book is very unapearent and you would have to actually look to find it. Another thing is that There isn't any character development and is unlikable. He doesn't follow directions, and he also has no flaws known. Many parts of the book seem useless and stretched out. Many character serve no purpose to the plot but is just there to waste paper. Like his friend on Earth that nobody cares about. The book also compares the past or our present day way to much to where it seems repetitive. I feel like the story should've started before it did. That way we'd get to know Dr.Holtz and get attached to him. The book overall just seems childish. If your older than 13 than I don't recommend this book.