Enable Cheat Menu:
At the Main Menu, press R1, Circle, Left, Triangle, Triangle. This will open up a new 'cheat' option.

Play as Armored Spider Man:
At the Character Selection screen, highlight Spider Man, hold select and press any punch or kick button.

Play as Mephisto:
At the Character Selection screen, highlight Omega-Red, hold select and press any punch or kick button.

Play as U.S Agent:
At the Character Selection screen, highlight Vega, hold select and press any punch or kick button.

Play as Shadow:
At the Character Selection screen, highlight Dhalsim, hold select and press any punch or kick button.

Play as Dark Sakura:
At the Character Selection screen, highlight Hulk, hold select and press any punch or kick button.

Play as Mech Zangief:
At the Character Selection screen, highlight Blackheart, hold select and press any punch or kick button.

Play as Mech-Gouki:
Beat the game once with any character. Then enter the Options screen and select "Same Character Mode". At the Character Selection screen, highlight Gouki (Akuma), hold Select and press any Punch or Kick button, then select Gouki again and press any Punch or Kick button.

Bonus options:
Beat the game without losing any rounds. Then, additional selections will appear on the options menu, including increasing the speed to eight stars and always having full combo meters.

Exploding Dan:
Hold WP after selecting Dan as your first character. Hold the button until the the word 'Fight' disapears

Extra jumps for Norimaro:
Select Norimaro, then hold WK+MK+HK until the word 'Fight' disapears

Cyber Akuma:
Beat Arcade mode without continuing. Now go into Battle or Vs. Mode, highlight Akuma and press Select 5 times, then X.

Apocalypse:
Beat Arcade mode without continuing. Now go into Battle or Vs. Mode, highlight Akuma and press Select 6 times, then X.

Faster game:
Choose a chracter and hold WK + MK + HK until the word "Fight" disappears.

Change order of characters:
At Vs. Mode screen, press all three Punch buttons to switch order.

Switch fighters:
Hold R1 + L1 + R2 + L2 after choosing your characters. Continue holding through the Vs. screen. You should now be controlling the second fighter.

Thanks to Revolution readers Alex San Juan, Patrick/Arnel/Paulo, BuX FaMiLy, Roy "Thunderbolt" Reyes, WaRheaD, Jose Daniel S. Rosales, Franc, Paolo M.Crisostomo, Shin Derek Rage, Jon "Golga" Garsya & "P", Javontay, Julian Cañita, Eli, Dee_Sickenen, Machel Barnes, and Kin James A. Gatmaytan!