Quake 4 Cheats

Cheat Codes
Press [Back] during game play to display the objectives window, then quickly press the following keys to activate the corresponding cheat function:

[Up]x2, [Down]x2, [Left], [Right], [Left], [Right], [B], [A] - Get all
[B], [A], [B], [A], [Up]x2, [Down], [X] - Health
[B], [A], [X], [Y], [Left], [Right], [Left] - Ammunition
[Down], [Up], [Down]x2, [Up], [Right], [Left], [Right], [Y], [X]x2, [A] - Never die

NOTE: If you want to get the Quake 4 achievements, do not use cheat codes. Once a cheat code is active the game will disable all achievements. If you have this problem on your saved game files, you must delete all of your current save files for the game and start again.

Xbox Live gamer points (single player mode)
Complete the following achievements to unlock the indicated number of Xbox Live Gamerscore points:

Private (Act 1): Complete Act 1 with the rank of Private (15 points).
Private (Act 2): Complete Acts 1 and 2 with the rank of Private (20 points).
Private (Defeated the Strogg): Complete the game with the rank of Private (25 points).
Corporal (Act 1): Complete Act 1 with the rank of Corporal (25 points).
Corporal (Act 2): Complete Acts 1 and 2 with the rank of Corporal (25 points).
Corporal (Defeated The Strogg): Complete the game with the rank of Corporal (30 points).
Lieutenant (Act 1): Complete Act 1 with the rank of Lieutenant (25 points).
Lieutenant (Act 2): Complete Acts 1 and 2 with the rank of Lieutenant (25 points).
Lieutenant (Defeated The Strogg): Complete Acts 1 and 2 with the rank of Lieutenant (30 points).
General (Act 1): Complete Act 1 with the rank of General (25 points).
General (Act 2): Complete Acts 1 and 2 with the rank of General (25 points).
General (Defeated The Strogg): Complete the game with the rank of General (30 points).
Untouchable: Complete a level without taking damage (10 points).
Blaster Master: Complete a level using only the blaster (15 points).
Hyperactive: Complete a level using only the hyperblaster (15 points).
Blazing Buckshot: Complete a level using only the shotgun (15 points).
The Machine: Complete a level using only the machine gun (15 points).
Tooth and Nail: Complete a level using only the nailgun (15 points).
Pineapple King: Complete a level using only the grenade launcher (15 points).
Ballistics Expert: Complete a level using only the rocket launcher (15 points).
Enlightening: Complete a level using only the lightning gun (15 points).
The Dark Lord: Complete a level using only the DMG (15 points).
The Sniper: Complete a level using only the railgun (15 points).
Full Arsenal: Complete a level where a shot with every weapon hits (20 points).
Solar Star of Courage: Fight alongside Viper Squad (Hangar2) (20 points).
Sky Marshall's Medal of Valor: Rescuing Pvt. Lanier of Eagle Squad (Waste) (20 points).
Galactic Order of Heroism: Fight alongside Raven Squad (20 points).