Computer Controlled Player
At the Character Selection screen, choose a character, then
move the cursor to the red pearl. Now press X + Y + Z and the
computer will take over your character.
Hidden Item Shop
Before the battle starts, move your cursor to BUY ITEM and press
Y, A, Down, X, B. A tone will chime and give you access to the
hidden item shop.
Buy enough items to access the second page of your inventory,
then unequip all of your weapons. At this point the second page
must be full. Now sell all your items starting with the last
item on the second page. Eventually you'll reach a point where
you're selling the same item multiple times. You can continue to
sell it until you have all the money you need.
At the LOAD Menu, press L, Y, Right, R, R, A + START.
This will allow you to jump to any scenario in the game.
Replay Old Missions
At the LOAD menu, press L, Y, Up, R, R, A. You can no replay
any scenario you've played before.
At the PRESS START screen, press A, Z, Y, X, A, Z, X, Y.