Press R1, R2, L2, R1, R1, R1, R2, L2, L1, L1 then press Square quickly. Your player should blow up and say, "What did you do that for?"
Hints
Take careful aim and go for head shots when you can.
Don't forget that grenades can do the trick when firearms can't.
A stealthy approach is best. Remember, you have a huge advantage if you see the enemy first.
How To Get A Flamethrower
When you get to mission 7, on the first level on the mission, there is a guy who's hiding. When you find him he will have a flamethrower. Kill this guy and you will have the flamethrower.
Invinciblity
Go to the password screen, type in "MOSTMEDALS". Then go to secret codes to enable it. NOTE - this only works on previously played stages.
And then go to War Records and select the Mission Log and you can choose the mission.
Secret Stuff From The Developers
It unlocks pictures of the developers relatives and is very weird. Type in the code at the password menu.
Code
Picture
COOLCHICK
Girl Picture
AJRULES
AJ Picture
DWIMOHTEAM
DEV. Team Pictures
The Ultimate Cheat
First: Go to the cheat screen and enter the following code: SMPSMDMILK. Then re-enter the cheat menu and enter URLINGAMBE. Then when you enter the cheat menu, you will have all the cheat codes. (Unlock all levels isnt included in this cheat)
Captain Dye Mode
This code makes it harder to complete the game because it keeps your life the same life from mission to mission (Example: if you finish one level with 50 percent you will start the next level with the same life.)