Also note, PPSSPP is a open source project, you should be able to find games that are open source or have an open source engine. Other games might not have an open iso file that you can play (gamedata can belong to game copyright holders), sometimes finding roms and game data from old open consoles might be fairly easy on github and data sites.
Tech Retro Gaming Hub Reading Time: 6 minutes Also note, PPSSPP is a open source project,