(6*7)-1 almost the answer
Hah, back by chance after three (or four?) years. This might become a game, depending on how the theme voting turns out, how my motivation and time keeps through the weekend, and whether the world ends Sunday before or after teatime.
Tools that might be used: Unity3D, Gamemaker, Blender, Javascript of some sort (Phaser?), Affinity Designer, MS Paint.
Hope everyone has lots of fun!