Cellular Automata!
best here:
https://turbowarp.org/722859698/fullscreen?turbo
click to add pixels
up / down arrow to change pen size
left / right arrow to change material
q to generate with new size
This project is super laggy for how simple it is. I really like making cellular automata, so I might make a javascript version with more materials like temperature changing state of water and sand (glass), ants, fire, and electricity though metal