Enter the following codes at the code menu: 

Code: Effect 

Get Max Ammo: MRJUAREZ
Be Invincible: LRGARMS
More Health: BUTTERUP
Get All Weapons: STRAPPED
Skip Level: QUITER
Slomotion Button: SLIZOMIZO
Bouncy Men: BOUNZMEN
Level Warp All: PASSKEY
Do Not Select: DONOTSEL
Get Clown Hero: SCARYCLOWN
Get SuperJohn Hero: SUPERJOHN
Get GI John Hero: GNRLINFANTRY
Get Nara Hero: WEIGHTGAIN
Get Nikki Hero: HAIRLOSS
Get Moseley Hero: BIGLIPS
Get Convict Hero: JAILBREAK
Get Robot Hero: MRROBOTO
Get Zombie Hero: IAMSODEAD
Get Lizard Hero: HISSSS
Dramatic Finish: STYLIN
Clutter the Place Up: CLUTZ
Get Max Damage: SPINACH
Get Ending Scene: WIMP
Get Armor: STEELUP
Get Rag Doll: CLUMSY
Unlock All Movies: DIRECTOR
Unlock All Combos: NINJA
Get Baseball Bat: SLUGGER
Unlock Pain Arenas: MAXIMUMHURT
Get Free aim: FPSSTYLE
Unlock Concept Art: SKETCHPAD