Do a search for these titles:
Eye of the Beholder
Lunar: Eternal Blue
Lunar: Silver Star
Shining Force
Popful Mail
Dark Wizard
Vay
These are all RPGs for the Sega CD/Megadrive.
But you mention a prince, and if that's accurate, it's most likely going to be Vay.
Check Vay here -
Sega CD Reviews