This book, as you know, will be very text-heavy. Be in no doubt, there's going to be a LOT to read. That doesn't mean, though, that there won't be a lot to look at, too. There will be plenty of screenshots... I've already accumulated hours and hours of gameplay videos and tons of screenshots.
Most of the time, those screenshots will be worked into a page of text. Every now and again, though, a game might have a full-page screenshot along with their text pages, with a quote from the programmer or artist being the only text on the page.
I think these pages will be good "impact" pages. They'll also help to break up the wall of text quite nicely... and anyway, who doesn't love a big full-page screenshot?
I also think that having my book in landscape format will help here. Screenshots can fit on a single page quite nicely in that format... as you can see below in this potential example from the Spectrum version of Midnight Resistance. That game will have a three-page spread, two of which will be largely text... along with this lovely-looking fella.
As ever, this could be subject to change and opinions are welcome. Would you like to see a number of pages like this in the book?
Oh, and Commodore 64 fans... I promise the next preview will be right up your street...