X-Men v. Street Fighter
Kick Him While He's Down
After winning a round, press START and you'll be able to kick or
taunt your defeated opponent.
Play as Akuma/Gouki
Highlight either Magneto, Juggernaut, Dhalsim or Vega and press UP.
You will see the face of Akuma. Press any button to use it.
Play as Apocalypse
At the Versus Mode character select screen, hold SELECT on Gouki
for five seconds, then press any punch button.
