if you enjoy 6502 machine code, I've dissassembled and commented LIFE (Conway's Game of for the the Apple-1).
The binary is 440 bytes, the disassembly is 388 source code lines, fully commented. You can open it here on my github page: https://github.com/.../blob/main/demos/life-src/life-src.asm
It took me several iterations before I could figure out it all, naming all variables, isolating subroutines and fully understand what they do. A lot of work, but also lot of fun!
The only thing I could not grasp in full is the random number generator (GETRAND routine at line 330): it seems to be a sort of LFSR but not like the ones I've seen so far. If you have any clue, please write down in the comments.