Back in 2006 I heard about the Atari 2600 homebrew scene and was fascinated to read about the mind-boggling tricks required to write a game for the system (like, coding to the TV raster beam... madness!). I went down the rabbit hole for a while and learned 6502 asm, and ended up with this "sort of a game" - https://github.com/mrspeaker/plops.
It was a great learning experience and certainly made me respect the devs of the day - who were performing miracles given the hardware constraints, and luck of modern debugging tools!
I've been into the 2600 homebrew scene since "Making Games for the Atari 2600" came out a few years ago. I haven't made anything useful yet, but the community is great and very active. There's an awesome twitch channel[1] dedicated to 2600 homebrew, ZeroPageHomebrew. They do 2 shows a week, ~2 hours each. The developers and various AtariAge people are usually active in the chat. They're doing an awards show in February for homebrews made last year.
It was a great learning experience and certainly made me respect the devs of the day - who were performing miracles given the hardware constraints, and luck of modern debugging tools!