Grand Theft Auto IV for Xbox 360 Reviews by Gamers

Cheat mode
While playing the game, press Up to display Niko's cell phone. Press Up again to access the keypad. Then, enter one of the following codes to activate the corresponding cheat function. Once a code has been entered correctly, a new "Cheats" menu option will be available on your phone, below "Options", where you can access the cheats without having to enter the phone number again. Note: Do not save the game after enabling a code to avoid unforeseen problems. Enabling some cheats may prevent achievements from being earned.

Full health and armor
Dial "3625550100" into the cell phone. Note: This phone number translates to "DOC-555-0100". This code prevents the "Cleaned The Mean Streets", "Finish Him", "One Man Army", and "Walk Free" achievements from being earned.

Full health, armor, and ammunition
Dial "4825550100" into the cell phone. Note: This phone number translates to "GTA-555-0100". This code prevents the "Cleaned The Mean Streets" achievement from being earned.

Weapons tier 1
Dial "4865550100" into the cell phone. This will unlock the baseball bat, handgun, shotgun, MP5, M4, sniper rifle, RPG, and grenades. Note: This phone number translates to "GUN-555-0150". This code prevents the "Cleaned The Mean Streets" achievement from being earned.

Weapons tier 2
Dial "4865550150" into the cell phone. This will unlock the knife, Molotov cocktails, handgun, shotgun, Uzi, AK47, sniper rifle, and RPG. Note: This phone number translates to "GUN-555-0100". This code prevents the "Cleaned The Mean Streets" achievement from being earned.

Remove Niko's wanted level
Dial "2675550100" into the cell phone. Note: This phone number translates to "COP-555-0100". This code prevents the "One Man Army" and "Walk Free" achievements from being earned.

Add one star to Niko's wanted level
Dial "2675550150" into the cell phone. Note: This phone number translates to "COP-555-0150".

Spawn Annihilator police helicopter
Dial "3595550100" into the cel