ghouls n ghosts -- that's a supergrafx-compatible title
supergrafx was a successor to the PC-Engine, of sorts - one that was pretty quickly abandoned, mind you. at any rate, it had hardware differences that is not supported in the current version of GPengine. perhaps in a future vers.?
sega Genesis version does a faithful recreation as well, hopefully a gen emulator will surface that supports this game (likely you'll see that sooner than supergrafx emulation on the GP32, I'd imagine)
--isn't there also an atari ST version of the game?