Enter at the title screen for the corresponding effect. NOTE: Use the D-Pad for the directional presses. The name of the cheat will be displayed to confirm correct entry (with the exception of "Blue Screen of Nerd", which will instead simply appear).

Effect	Code
"Blue Screen of Nerd"	Up, Up, Down, Down, Left, Right, Left, Right, B, A.
Big Head Mode	A, B, A, Y, A, B, B.
Hedgehog Mode	Up, Down, Left, Right, A.
Unlock all characters and levels	Down, Left, Left, Up, Right, Right, Up, Down, Left, Left, Up, Down, Up, Up, Up, Up.