Ascii World: minimalist pseudo-3D game in ASCII characters

Ascii World isn't a 3D shader, nor is it is a graphical toy. It's a complete 'isometric'-style game, like Monument Valley, that uses basic ASCII characters to draw (and define) all its forms and geometries. It's startlingly fresh, yet makes you wonder how much of it could be implemented on a Commodore PET. And it's maddeningly difficult!