Go into cheat mode to unlock Classic Characters:
Cheat mode is where you have to enter the cheat codes. You can find it by going into “Classic Arcade Mode”, and then enter the code for 1 of the 16 below listed characters you want. If you entered the code correctly, you will hear a sound. Please note: The classic character versions do not have super combos and cannot reduce throw damage.
Unlock new playable Classic Characters:
1. Classic Balrog code: Jab, Right, Left(2), Right, Jab.
2. Classic Blanka code: Jab, Left, Right(3), Jab.
3. Classic Cammy code: Jab, Up(2), Down(2), Jab.
4. Classic Chun-Li code: Jab, Down(3), Up, Jab.
5. Classic Dee Jay code: Jab, Down(2), Up(2), Jab.
6. Classic Dhalsim code: Jab, Down, Up(3), Jab.
7. Classic E. Honda code: Jab, Up(3), Down, Jab.
8. Classic Fei Long code: Jab, Left(2), Right(2), Jab.
9. Classic Guile code: Jab, Up, Down(3), Jab.
10. Classic Ken code: Jab, Left(3), Right, Jab.
11. Classic M. Bison code: Jab, Down, Up(2), Down, Jab.
12. Classic Ryu code: Jab, Right(3), Left, Jab.
13. Classic Sagat code: Jab, Up, Down(3), Up, Jab.
14. Classic T. Hawk code: Jab, Right(2), Left(2), Jab.
15. Classic Vega code: Jab, Left, Right(2), Left, Jab.
16. Classic Zangief code: Jab, Left, Right(3), Jab.
How to play as Akuma:
17. Select E. Honda in Training/Versus Modes (or Guile in Arcade Mode) on the Character Select screen and press Up.
How to play as Akuma on Classic Modes:
* In Classic Arcade mode you must highlight these characters for at least 2 seconds in the following order: Ryu, T. Hawk, Guile, Cammy, and Ryu again. Then, after highlighting Ryu for 2 seconds, press Start and all three punch buttons in quick succession (or simultaneously). If you did it correctly, Akuma’s portrait will replace Ryu’s.
* For Classic Arcade-Versus/Training mode, highlight Ryu, the random box beside Guile, Guile, Sagat then Ryu again.
How to fight against Akuma:
You must defeat all opponents before M. Bison within 20 minutes or less, and you cannot use a single continue. When you fight Bison, Akuma will appear; when Akuma appears perform the Shun Goku Satsu on Bison, and then Akuma will fight you.