Retroarch is a great emulator BUT the steam version is horribly stripped, thankfully this can be fixed with 2 minutes of work.

This emulator being on steam is amazing, it comes with a few preview cores to get you started, cloud saved settings via steam cloud (which i have disabled) and makes streaming games very easy via steamlink or on steamdeck.

The problem is, the default install of retroarch on steam is ~1.5 years old and the cores are horrible outdated.
Buuuuut if you right click it in your library > properties > game versions & Betas > set it to "nightly" you'll be on the latest, *nightly*, updated version of retroarch.
THIS DOES NOT PROVIDE UPDATED CORES THOUGH.
so how do you dear reader get all the cores into your steam version?

simple, go to: https://buildbot.libretro.com/nightly/windows/x86_64/RetroArch_cores.7z
this link will start the download for the always latest cores for windows.
follow the link backwards for linux or different architecture.
open the zip, go into retroarch-win64 > copy and paste the entire "cores" folder into your steam-retroarch's root folder.
Accept all ovewrites if asked and you're done.

Next step is to get the info files for these cores so that retroarch knows what it has.
go to https://buildbot.libretro.com/nightly/windows/x86_64/RetroArch.7z
This will install the latest version of retroarch's standalone emulator.
open the zip, go into retroarch-win64 > copy and paste the entire "info" folder into your steam-retroarch's root folder.
Accept all ovewrites if asked and you're done.

tadaaa, done, now you have all the updated cores from the standalone nightly updated retroarch into your steam version, which adds ~200 up to date cores instead of the 65 outdated cores we currently have on steam.


Now a couple more things i'd recommend changing for usability, since the default config for retroarch is extremely user unfriendly.
open retroarch > settings > user interface > scroll all the way to the bottom for menu driver > change it to XMB. save config and restart your retroarch.
it will now look like a ps3 and be way easier to control, enjoy!

El emulador de emuladores. Si te gusta la emulación y no lo tienes bajalo AHORA.
La interfaz es un poco complicada al comienzo pero dale un tiempo y te acostumbrarás con el tiempo.
Una vez configuradas los cores y las carpetas de ROM todo es bastante automático

10/10 emulator to play Advance Wars 2 on
Play Multiplayer!

and it's easy to use!