Super Street Fighter 2 Turbo
Fight as Gouki/Akuma (versus mode):
Choose versus mode from the title screen, then select the game
speed with the Fierce Punch button. Highlight Ryu and press every
button except the D-pad simultaneously. If you picked your character
first, keep holding these buttons until the second player makes
their choice. If the second player also wants to be Akuma he or she
will also have to hold all six buttons.
Play as Gouki/Akuma in (Super Battle mode):
Choose the Super Battle mode from the Title Screen and select the
game speed with the Fierce Punch button. Highlight Ryu for two
seconds, then move directly to T. Hawk. Pause on him for two
seconds, then move directly to Guile and wait for two seconds. From
Guile, move to Cammy by passing through Dhalsim (go down one
character, then right). After waiting on Cammy for two seconds, go
to Ryu by moving directly to Ken and then up onto Ryu. Pause on Ryu
for 2 seconds and then press all three Punch buttons and X
simultaneously.