Cheat Codes:

Start at the main menu, then select game, then option, then bonus. Hold down L1 and R1 and then enter the following code: down, circle, up, square, down, down, up, up (let go of the shoulder buttons when you are done).
Then from the main menu, select the cheat option and enter the following codes.
God Mode
8wonder
Unlock All Levels
KKst0ry
One Hit Kills
GrosBras
Revolver
KKtigun
Machine Gun
KKcapone
Shotgun
KKsh0tgun
Sniper Rifle
KKsn1per
Infinite Spears
lance 1nf
999 Rounds of Ammo
KK 999 mun
Bonus Complete
KKmuseum