I’m most familiar with PS1 Homebrew, its almost all available under the “Net Yaroze” name.

Without a Net Yaroze ps1, you’ll need a TonyHAX/freePSXboot memory card to boot the games. TonyHAX unlocks the region by resetting the disc drive into an unlocked state after Boot. As a consequence, this also allows homebrew titles and less than legitimate copies of titles to boot. Don’t use this for piracy, that would be iLleGaL.

Archive.org has 3 Net yaroze game jams available, one of which has 83 titles but they usually render black and white. There is also Fromage, a ps1 demake for Minecraft (barely functional, but neat to show friends)