At the Main menu, tap Up, Up, Down, Down, Left, Right, Left, Right, A, B, Start, Start for all 8 spandex costumes and all characters.
One hit kills: Up, Up, Down, Down, X, Y, Y, X
A.I. Toggle: Up, Up, Down, Down, A, A, B, B, X, X, Y, Y
Super Meter filled: Up, Up, Down, Down, A, X, A, X