@@MitchHutsell I think it's unlocked via one of the stars. Every star in this port unlocks a cheat (I.E. collecting a star in one of the acts unlocks the ability to turn off the color resistance on enemies)
@@MitchHutsell I had a similar error to happen to me as well when I first tried it. It worked for me after I had defeated the final boss as all characters
No wonder why Final M Bison was so hard to beat. I remember where I watched Maximillion Dood's boss rage video where he gets wrecked by Final M Bison. 😒 Although, I do like His theme song, Brave or Grave.