Hidden Player
     First  clear the game's Final Stage and save it to a memory card.
Cynthia will now be available.

Make Own Puzzles
     First clear the game's Final Stage, and save it to a memory card.
Now  go  into  Options  and select Game Mode. Choose System, and press
Right to turn Original Mode On. Exit Options and select the 1p game.

Play as Spike
     Beat the game with Cynthia and have an IQ over 400.

Play Demo Levels
     At the Rules, highlight either Demo 1, 2, or 3, then hold L1 + R1
and press X.