Unlock Secret EX Characters and Nightmare Geese in Real Bout Fatal Fury Special:
Allow the demonstration to run until the 'Ranking Screen' appears and then enter the following codes to unlock the corresponding secret character.

Unlock EX Andy:
Hold L1 and Press X Or Circle Over Andy.

Unlock Ex Blue Marry:
Hold L1 and Press X Or Circle Over Blue Marry.

Unlock EX Tung Fu Rue:
Hold L1 and Press X Or Circle Over Tung Fu Rue.

Unlock EX Billy Kane:
Hold L1 and Press X Or Circle Over Billy Kane.

Unlock Nightmare Geese:
Do a counter clockwise 360 motion starting from the Right and when you get to the Down-Right motion, hold it and press LP, LK, HP. If you have entered the code in correctly Geese will say 'Come on' as confirmation and Geese's portrait will now be on the 'Select' screen.

In Real Bout 2 you can play as Alfred by holding LK + HP on any character portrait so you see the portrait change to Alfred. While still holding LK + HP, select the character with either LP or HK.