Street Fighter Zero 2
Play as Shin Akuma:
Move the cursor over Akuma, press and hold the Select/Taunt button and move the cursor to Adon, Chun Li, Guy, Rolento, Sakura, Rose, Birdie, Akuma, M. Bison, Dan, Akuma and press any button.
Play as the original Chun Li:
Press and hold the Select key over Chun Li's face for about 8 seconds and press any button.
Thanks to Revolution readers The Shade, Matthew Ho, Ben, and Justin Chan Boon