This involves downloading PlayStation bios and finding PlayStation ROMs. Now that Xbox Dev Mode is activated, and Retroarch is fully installed, you'll need to find some PS1 games. Playing PS1 games on your Xbox Series X|S You're done! Retroarch is installed and ready to go. Once that's done, the screen will flash black for a moment, and then your menu will look a lot cleaner.You'll notice that the menus look a little primitive, but we can fix that by scrolling down to the Online Updater and then Update Assets.
Now Retroarch will install onto your Xbox. Source: Windows Central / Zackery Cuevas (Image credit: Source: Windows Central / Zackery Cuevas)