Modern Vintage Gamer, who ran his tests on an Xbox Series S, proceeded to demo a variety of older games running off the RetroArch emulator, including God of War, Metal Gear Solid 2, Silent Hill 2, and more.
Confirmed Xbox Series X Games
Although not official, it certainly appears that the Xbox Series X|S can play more PS2 games than the PS5, which only supports backward compatibility for PS4 games and select PS3 games through PS Now.
Check out Modern Vintage Gamer’s YouTube channel for a full rundown on their experiments with the Xbox Series S Developer Mode. Although tested on an Xbox Series S, they said the Xbox Series X should be on par, though not necessarily better than the Series S.