I am very happy that someone decided to make a Jam based on the concept of unplayable games. I am so excited about the things I want to make for this and to see what everyone else comes up with. For anyone looking for inspiration on this, there is a rather comprehensive book on fictional games called "Fictional Games: A Philosophy of Worldbuilding and Imaginary Play" by Stefano Gualeni and Riccardo Fassone. This by no means covers all kinds of unplayable games, but it's a good start.