To fight Akuma, make sure your score is less than 500,000 when you meet M.Bison
At the character select screen, go to Ryu for 2 seconds.
Then go to T-hawk for 2 second.
Then go to Guile for 2 seconds.
Then go to Cammy for 2 seconds.
Then return to Ryu, wait 2 seconds, then press Jab.
Select the Versus mode and set the speed. when you select a character, simultaneously press A, B, C, L, R, and P. Hold down these buttons until your opponent has selected their character. Akuma's silhouette appears on the Stage Select screen. On the Result screen Akuma's record is listed under the name "Gouki."