After choosing a difficulty and before selecting a mission, press: C-Down, R, Z, C-Right, C-Left. If you've done it correctly, you'll hear Ethan say, "Ah, that's better."
Fast Mode
At the level select menu press c-up z c-up z c-up z c-up.
Get Haunted by Bad Guy's Ghost
Go to the very first mission and start. This cheat may work with the rocket launcher, UZI, 9mm, and silencer codes. Go to the portable. stand close by and watch were the guy runs when he comes out. when he comes back, go in, kill him and use the face mask. Come out and take out a gun and head to where the guy went before. Make sure the second guard straight head, near the other portables is in front of you. Shoot him down and run to the electric panel ahead. You can blow it up if you want (depending on your objectives). It may take a few tries, but the guard should come back as a half dead person (ghost)and shoot at you. You will be affected, but not him.
Giant Head Mode
After choosing a difficulty and before selecting a mission, press: C-Down, L, C-Up, C-Right, L. If you've done it correctly, you'll hear Ethan say, "Ah, that's better."
Note: If you use these codes, you may not be able to complete some missions. To return to normal, you must reset your system.
Have All Objectives Done
At game selection screen press C down, C down, R, L, and Start. Once your done Ethan will say "Ah thats better." This code'll let you have all objectives done when you first start. You can just walk to the end.
Here are a few cheats to get you started
Enter these at the level select screen:
Invincibility - R,Z,C down,R,R.
Infinate Ammo - C up,Z,C left,Z,C left.
High Powered 9mm Pistol - R,L,C down,C up,C down.
Uzi with 30 rounds - C right,C left,C right, C down,C down.
7.65 Silenced Pistol - C up,L,C right,C left, C down.
Little kid mode
After choosing a difficulty and before selecting a mission, press: C-Down, C-Up, R, L, Z. If you've done it correctly, you'll hear Ethan say, "Ah, that's better."
Mini-Missle Launcer
Press R,L,C-left,C-right,C-down.
Red Dress
As soon as you get to the main menu, press z ten times very fast, the screen will turn red if you have done it correctly. The hold the a and b buton, and at the same time push start. Tom Cruize will have infinite eveything, and have a red dress throughout the entire game.
The Piano Player Glitch
The first thing you need to do is put in the cheat for the mini-rocket launcher (R, L, C-Left, C-Right, C-down) at the level select screen. Then select the embassy as the level. Once you are in kill all the guards with the mini-rocket launcher. Then head towards the piano player. When there punch him and you'll knock him off of his chair. He'll be dead sitting on air!
Uzi
For a uzi with 30 rounds push c-right c-left c-right c-down and r at the level selection screen. if it is done correctly you'll here Ethan say "Ah, that's better."