I forgot to mention that a playable prototype does exist for the Neo-Geo Pocket handheld system. In all honesty, I am not sure if one exists for the MVS/AES and CD systems, though. I did hear that a very wealthy collector has an MVS version, but refuses to dump the ROMs. This is all hearsay and it cannot be proven, since no name was ever given. Maybe we will see it someday, if any truth is behind the story.