I really, really like The Laser Game Tutorial
Tutorial: Squeak Development Example for Squeak 3.9
A.K.A. "The Laser Game Tutorial"
This excellent tutorial by Stephan Wessels will guide
you through installing Squeak, to creating a fun game using the Morphic graphics system, all > while observing solid object-oriented design principles
It is divided in 6 Sessions so 1 each day although I must say each session has taken me two hours or so.
Perfect for your objectives.