The Incredible Hulk: Ultimate Destruction Cheats

Cheat mode
Go to main screen, press [Y], and press [Right] until the "Extras" option is selectable. Press [A]x3 to access the code input and enter one of the following passwords. Note: Some codes require that you find the comic that unlock that particular cheat before it can be enabled:

BRINGIT - Double health power-up values
DESTROY - Double damage from Hulk
RETRO - Black and white graphics
HISTORY - Sepia tone graphics
OCANADA - Canadian flag shorts
DEUTSH - German flag shorts
MUTANDA - Italian flag shorts
FURAGGU - Japanese flag shorts
BANDERA - Spanish flag shorts
FSHNCHP - U.K. flag shorts
AMERICA - U.S. flag shorts
SUITFIT - Joe Fixit (Gray Hulk) skin
VILLAIN - The Abomination skin
PILLOWS - Low gravity
CABBIES - All vehicles are taxis
TRANSIT - All vehicles are buses
FROGGIE - Aggressive traffic (doubles the speed of traffic and removes the veer functionality)
KINGKNG - Big blue gorilla balloons
CHZGUN - Cow missiles
SMASH5 - 5,000 Smash Points
SMASH10 - 10,000 Smash Points
SMASH15 - 15,000 Smash Points

Smash point levels (demo version)
Level 01 - Bruce Banner - TRY AGAIN
Level 02 - Spiller of Milk - MUTANDA
Level 03 - Puny Monkey! - SMASH5
Level 04 - Puny Human! - FSHNCHP
Level 05 - You're Not Really Trying! - OCANADA
Level 06 - Big, Green And Useless - SMASH15
Level 07 - Merely Annoying - BANDERA
Level 08 - Hulk Smash! - DEUTSCH
Level 09 - Civil Disaster - CABBIES
Level 10 - Sheer Carnage! - SMASH10
Level 11 - Mass Destruction - FURAGGU
Level 12 - Catastrophic Destruction - DRAPEAU
Level 13 - Total Devastation! - AMERICA
Level 14 - Strongest One There Is - RETRO
Level 15 - Ultimate Destruction! - BRING IT
End - God - HISTORY

Suicide
Grab a civilian and go to the top of a tall building. Press Triangle and wait a moment. They will try to run away, but fall off the building.

Indestructible cows
In the badlands area, if you pick up a cow you can use it an unlimited amount of times as a bludgeon that will never break.