An amazing account of the two Johns. I was obviously more bent towards Carmack, him being a programmer, but this book beautifully highlights the ups and lows of the journey. It leaves you waiting for more, and I wish to hear more of this story. Even though it focuses mainly on the two Johns, this book is not a biography. Rather it is an account of the Silicon Valley Gaming & Startup Scene in the 80-90s. I would go so far ahead to label this as a "startup-book", with two entrepreneurs making it big time.
The book doesn't end on much of a high note, ending with the launch of Quake III Team Arena and Carmack firing his rockets. It would be awesome if the author came up with a DLC for the book with more chapters covering what both of them have done in the past 13 years.