I don't have any recording features set up but yeah retropie is pretty fun. It's nice to change the inputs on your tv and just select a console and play. I play a lot of Mario Kart 64, Mario 3, etc when my cousins are in town. It's a nice throwback and we get pretty competitive with it.
MK64 is one of my go-to games when I'm burnt out with speedrunning other stuff. I never record or submit times for it just to try and keep it as a sort of casual speed game I'm not too serious about. F Zero X is similar.
I've thought about putting a pi inside a controller as a sort of handheld console, but I haven't come across a suitable one yet. My main controller can be used for any console, but there would not be enough space inside it.
The real fun w/ pi is setting up a modern wireless controller. I use my wireless ps style controller for 16 bit and earlier games that love a d-pad. I use my wireless 360 controllers for stuff like mk64. It's such a tiny device you can hide easily behind the flat screen and just have some controllers about. I'm waiting on Pi4 but my Pi2 does more than 40 consoles pretty easily. It struggles on some N64 titles but plays others perfectly. Thousands of games all selectable from the controller alone.
It's pretty easy to finish casually, my first playthrough took just over 10 minutes with no prior knowledge about the hack.
You got retropie set up? I use retroarch on desktop sometimes when I'm just playing stuff casually, it's quite convenient to switch between games/consoles. Unfortunately my recording software does not agree with it, so I do all my runs on separate emulators.