As of Mame .64 you can select to play the US (6 button) or Japan (2 button) mode in this game by a dipswitch (which represents a jumper on the pcb), this is how the game determines the region for this particular game so a Japan romset isn't going to show up since its the same just with a different dipswitch / jumper setting.
I was wondering, since in this case this makes quite a difference to the way the game is played rather than just the language changing should it be split? It would be interesting to see recordings made in both ways.
Daioh
Moderator: BBH