I've also made a space invader generator.

live version: https://abetusk.github.io/iao/vadfad_1gen/

source: https://github.com/abetusk/iao/tree/main/vadfad_1gen

Inspired by Jared Tarbell (linked from another comment here from levitated.net).

I found it surprisingly easy to get good results. The major components are the eyes, bilateral symmetry and otherwise random pixels within a small rectangle, if I remember correctly.