At options screen, hold L and press C-right, C-left, C-left, C-right, C-down, C-up, C-up, C-down, C-left, C-right, C-right, C-left, C-right, C-left. If you did this right you should get into a fight every 5 to 20 sec.!!
NOTE:This code must be re-entered each period.