Cannon Spike Codes -

Alternate costumes:
Highlight Cammy and press Up or Down at the character selection screen.

Gallery Art option:
Successfully complete the game under any difficulty setting as various characters to unlock the entries in the gallery option.

Mega Man and B.B Hood:
Successfully complete the game as any character under any difficulty setting. Press Left or Right at the character selection screen until Mega Man and B.B Hood appear.