5 extra missions in Mission Mode.

On the mission mode screen Press:
Code .................................. Effect
UP, DOWN, LEFT, DOWN, RIGHT, UP, SQUARE It will unlock 5 extra missions that are also in Collectors Edition.

Unlockables
Difficulties

When you beat the game on any difficulty, you unlock a higher difficulty.
Unlockable ............................ How to Unlock
Hard .................................. Beat the game on Normal
Master Ninja .......................... Beat the game on Very Hard
Ninja Dog ............................. Die 3 times
Very Hard ............................. Beat the game on Hard