I dunno if you'd wanna waste a whole sd card for a single game when you could fit hundreds on it.

I looked but there doesn't seem to be a straightforward way to do that in Linux. I was thinking a udev rule but it would be clunky since the low level details for media like SD cards aren't available. At best, maybe a generic rule that mounts it and looks for an autorun.sh or something, but that's basically reinventing Autoplay on Windows and would have the same security implications.

I read Hack-a-Day frequently, and I've come across several projects that use NFC readers so you can tap a card to play specific songs or start playlists. Maybe something like that but launch a specific game instead?

e.g. https://hackaday.com/2025/03/31/a-music-box-commanded-by-nfc-tags/

I think you might want to have a look at a MiSTer fpga.

(it provides a very authentic experience and can launch games with tags if you choose so)