Secret Levels:
At the game mode selection screen, press UP to enter a Secret Mode screen. Do these footsteps to get the secret modes in this order:
Another:
Up, Up, Down, Down, Up, Up, Down, Down

Maniac:
Left, Left, Right, Right, Left, Left, Right, Right

Double Another & Maniac:
Up, Up, Down, Down, Left, Right, Left, Right

Mirror Another & Maniac:
Left, Right, Left, Right, Left, Right, Left, Right

Harder levels:
To make all levels harder go to Secret Mode screen and press: Down, Down, Down, Left, Left, Right, Right. That is too make all levels harder for experts only

Secret characters:
When at the main screen where you choose' Arcade Mode' or 'Arrange Mode'. Select the mode you want but don't press Circle yet. Hold the LEFT arrow and press Circle for a Secret BOX Character Hold the RIGHT arrow and press Circle for a Secret PEACE Character

All secret modes:
Select either arcade or arrange (append) mode at the title screen. Then, press Up at the difficulty selection screen to display the "Secret Mode" screen. Press Up, Up, Down, Down, Up, Up, Down, Down, Left, Right, Left, Right, Left, Right, Left, Right, Left, Left, Right, Right, Left, Left, Right, Right, before the timer reaches zero.

Versus mode:
Press Down + Start on controller two at the mode selection screen to unlock the versus mode option.

Alien and Tama Kid opponents:
Highlight "Arrange Mode", then hold Left and start the game.

Question Mark Man opponent:
Highlight "Arrange Mode", then hold Right and start the game.

Songs:
"Make A Jam" song: Complete the game under normal mode ten times.
"Paranoia KCET" song: Complete the game under hard mode one hundred times.
"Boy" song: Complete the game under hard mode three hundred times.
"I Believe Miracle" song: Complete the game under hard mode four hundred times.
"Paranoid Max" song: Complete the game under hard mode five hundred times.