At the main menu press X, X, Y, Y, X, Y, X, Y. When your done hit resume game. When you shoot someone gore will splirt out.
Unlock All Levels And All Game Modes
During gameplay enter "X, X, X, A, Left, Right, Left, Right, X, X, X, A, Left, Right, Left, Right". Return to the main menu, and under New Game all modes will be unlocked.
All Weapons, Level Select
Beat the game on Dead or Alive mode after you have unlocked it. At the main
menu, hold down Right Trigger + Right analog stick (click it in) + Left Trigger
+ Left analog stick (click it in). While holding those 4 buttons down, quickly
press; White, Black (2), White (2), Black. The Cheats menu will now be available
on the main menu. This cheat menu unlocks All Weapons and level select. To use
these cheats, press the Back button during a game to return to the main menu,
enter the Cheats menu, select the cheats you want to activate and then resume