A Pokemon Leaf Green 386 hack I did myself with minor changes (including starting with the National Dex ) Be sure to read the Notes.txt file BEFORE you start playing the game! Apply the patch to a clean US version Leaf Green rom (release #1637)
Not sure about other models of Pi4 but the Pi 4 B with 8GBs OCed to 2Ghz handles PSP really great except like 1 game I found and it is playable it just looks bad lol Motor Storm Arctic something or other.