(Author here) That's the Roguelike tutorial I created, not the Hands-on Rust book. The two are quite different beasts, with a bit of overlap.

Hands-on Rust is designed for the newcomer to Rust, and carefully maps tutorial sections through teaching beginner-to-intermediate Rust concepts. It starts with some basic Rust exercises, works through a Flappy Bird clone, and then uses Roguelike development to teach a lot of underlying Rust concepts. It also teaches gamedev, and tries to do so in a way you can reuse in other games.

The tutorial is all Roguelike, all the time - focused on building a working roguelike.