when the main menu screen appears, highlight the options menu and press X, X, Y, Y, Left analog x2, Right analog x2, L trigger x2 and R trigger x2
go into the options menu and ya should have a cheats menu above the other options, if not keep tappin the cheat in but watch out when tappin the left and right ananlog sticks since ya can nudge them which throws off the cheat
in the cheats menu, ya will get a level select, exp level increase and enemy intelligence level( if detect ya or not when sneakin into a base)
(Only works in two player)Get to the level Cavalry Charge. After watching the tank ahead of you explode, go around it and ram your tank into the cement pilars blocking you from driving up the slope. Have Connors stand behind the tank and shoot at while the other player is still giving the tank gas. If you shoot the ground at the center under the tank it will bump the tank up, and over, but kill the men in the tank. Heal them, and get in the tank, drive up the slope, blow up the other tank and kill the guys. Then command all your guys to get on the tank leaving one behind (player 2). Get everyone to jump or drive off the edge. If everyone dies at the same time, it will make a different explosion sound, and when it says mission failed, choose to restart the level. If the cheat is done right, every guy will have every gun available.