I was greatly disappointed with this book because none of the 'Game' examples had a graphical interface to them. They are all text based. Reading further in this thread people are suggesting Realm of Racket as an alternative and it looks like that book has much more visual game examples: https://realmofracket.com/games.html
That's not really a bad thing...
If you want graphical games in Lisp, take a look at the series called "Pushing pixels with Lisp":
https://www.reddit.com/r/lisp/comments/6d5nht/pushing_pixels...