Hidden Invasion Cheat Codes for Playstation 2

Big head mode:
Quickly press Left(2), Up(2), Right(2), Down(2) at the title screen. A sound will confirm correct code entry.

Oogie Boogie mode:
Quickly rotate the Left Analog-stick counter-clockwise four times at the title screen. A sound will confirm correct code entry. Many objects will be bouncing during game play.

Easy mode:
Quickly press Up, Down(2), Up, Left(2), Up, Right(2), Up(3) at the title screen. A sound will confirm correct code entry.