Enter these codes either at the main menu or in-game to activate.
|UP UP DOWN DOWN LEFT RIGHT LEFT RIGHT||Infinite Ammo|
|UP DOWN LEFT RIGHT UP DOWN LEFT RIGHT||Unlock All Stages|
Watermark 20 Code:
At the pause menu screen enter ZZZCZZCCZ to toggle the Watermark 20 code on or off. You will hear cheering and clapping after performing an execution if it is on.
Complete the game to unlock this option which allows any level to be replayed, as well as the "Release Therapy" bonus level.