Princess Crown wasn't made by Vanillaware, though, because it didn't exist back then, but it was directed by George Kamitani, the studio's founder, so some regard it as Vanillaware's legacy. He also worked on Capcom's D&D the Tower of Doom arcade game as a designer. Dragon's Crown was said to be paying homage both to that and Princess Crown.
Actually, now that you mention it, Atlus or Sega or whoever owns the bloody copyright should do sth about it and make a remaster. It hasn't even been officially translated for crying out loud, even though it scored a PSP port.
I believe the made some kind of saturn emulator to run the game on psp. It was called girigiri or something, translation would require hacking since no source code.