When the "Unlimited Focus", "Unlimited Health", "Unlimited Ammunition", and "Maximum Firepower" are enabled simultaneously, the game places a grenade or bomb right where you start the level (only on some levels). It does not kill you, but will knock you for a loop. For example, on the "Agent On Board" level, you start out besides Axel. If one of those cheats are enabled, the bomb will blow up Axel and you will die, ending the game. You have to play this level without cheats in order to complete it. The way to get away from the bomb is run before it explodes.
Activating cheats can also cause other undesirable effects in the game. For example, when fighting Agent on Board and attempting to knock him off the plane, he will carry an MP5 instead of being unarmed.
When using codes such as "Unlimited Health and "Unlimited Ammunition" on the Catching A Plane level, when the last intermission sequence is loading the game may exit.
The Water Way level will prevent you from getting the flashlight while using the "Unlimited Ammunition" code on.
Having too many codes on in the Airport level may freeze the game at the end. When you get close to the end of the level, a loading screen will appear and turn black. You will have to reset the game to continue.
If you have cheats enabled when loading the mission named "Malachi And Bane 2", the screen will turn black and the game will freeze. If codes are enabled you must reset the game and replay the "Malachi And Bane" mission in order to continue. After the level is completed, you will be able to save.