Big head mode:
Successfully complete the game under the easy difficulty setting. Press X, A, Y, B(3),
Up(5) on controller D when the game returns to "Press Start Button" screen. A sound
will confirm correct code entry. 

Mirror mode:
Successfully complete the game under the normal difficulty setting. Press L, Left, L,
Right, L, Down, L, Up, R, Left, R, Right, R, Down, R, Up on controller D when the
game returns to "Press Start Button" screen. A sound will confirm correct code entry. 

Random mode:
Successfully complete the game under the hard difficulty setting. Press B, Left, X, Y,
X, Y, B, A, B, A, Right, Left, Right, Left on controller D when the game returns to
"Press Start Button" screen. A sound will confirm correct code entry.