This is awesome work, and also a truly great writeup! I particularly enjoyed the outline of iterations to improve performance. Thank you very much for putting this together!

Emacs in general has great potential as a truly general programmable environment, and this is an amazing illustration of these abilities.

CHIP-8 brings back memories.

There's a pile of COSMAC-VIP magazines somewhere in my parents' basement. Writing an emulator and typing them in seems like it would be a fun project.

Wow, that was an excellent post. I love that they ended up contributing back to a couple projects as they found bugs or lack of functionality with them.

An improvement on the classics:

M-x tetris.

or if your the text adventure type

M-x dunnet

(M-x usually is "esc -x")

By default M is Meta or Alt not esc

All these things emacs does, and yet is still a sub-par text editor.