Play as Sho:
Only works if Gaia code has been entered. Play as Gaia and lose to computer. Do not continue; just let the time run out. When the title screen appears and as the options come together, press R, L, R, L, and S on Controller 2. Again you will hear "Fight!"
At Player Select screen, put cursor on Kayin, press and hold D, and press S.

Secret Normal Moves:
First, enter the Sho and Gaia codes. Next, wait for the demo and press START. As soon as the title screen comes up press Down+Left+X. After you hear a voice shout "Fantastic!" go to the Option menu. Change the shoulder button controls to your special moves. Now, start a game. At any point during the fight press R1+R2+L1+L2+select to use your characters secret normal move.

Desperation moves on command:
First set controls to 'easy' or 'very easy,' then activate Special Moves. When life reads red, press R1+R2+Down Simutaneously.

GameShark Codes

Infinite Health P1	801bc1880000

 
Infinite Time		801ca6e80b3a

 
Select Gaia		801bc11a0008

 
Select Sho		801bc11a0009

Thanks to Revolution readers Matt Neville and Evin Callahan!