The point is that their "isomorphic" graphics library generalizes over only the typical capabilities of early 1980s 8-bit systems with sprites etc. X11, Wayland

The point is that their "isomorphic" graphics library generalizes over only the typical capabilities of early 1980s 8-bit systems with sprites etc. X11, Wayland etc have a thousand times as much capability. Their solution is possibly an elegant solution to their problem space, without the ability to generalize much further than that. As far as I can see from the material. In the link I gave, the names of the library functions, and shortness of that list, suggests that all by itself.