Unlock Vs. Computer Mode:
Type in PERKINS at the Password entry screen.

GameShark Codes

Infinite Health
eb1f159400000003

Infinite health-(Player 2)
4dd212d600000003

Infinite Credits
6f8b665e0000009

Golden Hands(Original Mode)
614b665e00000012

M.Cocktail(Original Mode)
a3135c8e00000013

Pian Killer(Original Mode)
3c31295800000015

Sulfuric Acid(Original Mode)
F3d99b9900000014

Zombie Mode
c49baaf500000040]

Invisible Mode
4b3e52c4000000ff

Big Heads
c49baaf5000000F2

Silencer Mode
c49baaf500000020

Thanks to Revolution readers Erik Walker and Johnny "The Mad Typer" Liu!