A Reddit video posted by u/Yzenxam shows a PS5 with modified software running XPSemu, a PS5 version of Xemu for original Xbox games.
The demo includes Halo 2 and Forza Motorsport.
Crash Bandicoot is also visible as installed, but the article does not say it was running.
XPSemu is available on its creator ZiZc3’s GitHub page.
https://en.hacks.gr/to-ps5-mporei-na-trexei-paichnidia-toy-protoy-xbox-meso-toy-xpsemu/