The Orange Box Cheats

(Half-Life 2) Restore Health
Enter the code while playing Half Life 2. No specific requirements other then the game. Can be entered at any time on any level.

[Up] [Up] [Down] [Down] [Left] [Right] [Left] [Right] [B] [Button] [A]: Restore Health By 25 Points

(Half-Life 2) Full Ammo
If you're in need of ammunition for your currently-equipped weapon during any Half-Life 2 episode, insert the following code to max out your ammunition: Y, B, A, X, Right Bumper, Y, X, A, B, Right Bumper.

(Half-Life 2) Invincibility
Left Shoulder, Up, Right Shoulder, Up, Left Shoulder, Left Shoulder, Up, Right Shoulder, Right Shoulder, Up: Invincibility.

Achievements
Complete each achievement to get the allotted gamerscore.

"Radiation Levels Detected" (5): Get through the toxic tunnel under City 17 in Half-Life 2.
Acid Reflex (5): Kill an acid antlion worker.
Anchor's Aweigh! (5): Get the airboat.
Aperture Science (40): Earn gold medals on all Portal challenges.
Atomizer (10): Disintegrate 15 soldiers by throwing them into a Combine ball field.
Attica! (5): Destroy the gunship in the hospital attic.
Barnacle Bowling (5): Kill five barnacles with one barrel.
Basic Science (10): Earn bronze medals on all Portal challenges.
Blast from the Past (10): Find the HEV Suit Charger faceplate in Eli's scrapyard.
Bone Breaker (5): Kill 30 enemies with thrown physics objects.
Bug Hunt (10): Use the antlions to kill 50 enemies.
Cache Checker (10): Find every radar cache in chapter Under The Radar.
Camera Shy (5): Detach security cameras from the walls.
Car Crusher (5): Use the cars to squash 15 antlions in Episode One.
Citizen Escort (15): Don't let any citizens die when escorting them to the escape train.
Conservationist (5): Kill five enemies with the same energy ball.
Containment (5): Contain the Citadel core.
Counter-Sniper (5): Kill all of the snipers in City 17.
Cupcake (10): Beat two Portal advanced maps.
Deadly Harvest (5): Kill an enemy by planting a hopper mine.
Dynasty (10): Win 20 games.
Elevator Action (10): Survive long enough to get on the parking garage elevator.
Escape From City 17 (20): Escape City 17 with Alyx.
Fight the Power (10): Shut down the supression device by disabling its generators.
Flamethrower (5): Set five enemies on fire in 30 seconds.
Flushed (5): Kill an enemy with a toilet.
Follow Freeman (10): Gain command of a squad of rebels in the uprising.
Fratricide (5): Do whatever it takes to survive.
Friendly Fire (5): Knock down a turret with another turret.
Fruitcake (20): Beat four Portal advanced maps.
Get Some Grub (20): Squish every antlion grub in Episode Two.
Giant Killer (10): Survive the rooftop strider battle in the ruins of City 17.
Gordon Propelled Rocket (5): Unlock the rocket launcher lambda cache in chapter Under The Radar.
Grave Robber (5): Steal a Zombine's grenade.
Grey Matter (5): Get 25 headshots as a Sniper.
Hack Attack! (5): Kill five enemies with a Manhack.
Hard to Kill (10): Get five kills in a row without dying.
Hardcore (15): Accumulate 1000 total kills.
Head of the Class (5): Play a complete round with every class.
Heartbreaker (10): Complete Portal.
Heavy Weapons (5): Get the airboat's mounted gun.
Hit and Run (5): Run over 20 enemies with the car in Episode Two.
Hot PotatOwned (10): Kill a Combine soldier with his own grenade.
Impenetrable Defense (10): Successfully defend Dustbowl without giving up a capture.
Impossible Defense (30): Successfully defend Gravel Pit without giving up a capture.
Into the Breach (5): Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.
Keep Off the Sand! (20): Cross the antlion beach in chapter Sandtraps without touching the sand.
Lab Rat (5): Acquire the fully powered Aperture Science Handheld Portal Device.
Lambda Locator (15): Find all lambda caches in Half-Life 2.
Lightning Offense (10): Win Well in 5 minutes or less.
Little Rocket Man (30): Send the garden gnome into space.
Live Bait (10): Help Alyx snipe 30 enemies in Episode One.
Long Jump (5): Jump 300 feet.
Malcontent (5): Escape the apartment block raid.
Master of Disguise (15): Trick an opposing medic into healing you.
Neighborhood Watch (35): Save all buildings outside the missile silo from destruction.
Nemesis (5): Get five revenge kills.
One Man Army (5): Destroy six gunships in Half-Life 2.
OSHA Violation (5): Kill 3 enemies using the crane.
Pacifist (10): Contain the Citadel core without killing any stalkers.
Partygoer (5): Make the correct party escort submission position decision.
Payback (10): Kill a Hunter with its own flechettes.
Pedal to the Metal (5): Beat DOG in a race to the White Forest base.
Pinata Party (5): Find and break every web cache in Episode Two.
Plaza Defender (10): Survive the generator plaza standoff in chapter Anticitizen One.
Powerhouse Offense (5): Win 2Fort with a shutout.
Puttin' On a Clinic (15): Defeat the chopper in Episode Two without any misses.
Relentless Offense (20): Win Hydro without giving up a capture.
Revenge! (10): Destroy the hunter-chopper in Half-Life 2.
Rocket Science (20): Earn silver medals on all Portal challenges.
Targetted Advertising (5): Pin a soldier to the billboard in chapter Highway 17.
Team Doctor (5): Accumulate 25000 heal points as a Medic.
Terminal Velocity (5): Fall 30,000 feet.
The One Free Bullet (40): Beat Episode One firing exactly one bullet. Grenade, crowbar, rocket, and Gravgun kills are okay!
Think Fast! (10): Kill an Elite Soldier with his own energy ball.
Trusty Hardware (5): Get the crowbar.
Turret (5): Accumulate 10 turret kills with a single turret.
Two Points (2): Use DOG's ball to make a basket in Eli's scrapyard.
Vanilla Crazy Cake (30): Beat all six Portal advanced maps.
Vorticough (13): Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Warden Freeman (10): Survive the second turret standoff in Nova Prospekt.
Watch Your Head! (5): Make it to the bottom of the Citadel's main elevator shaft in one piece.
What cat? (5): Break the mini-teleporter in Kleiner's lab.
With Friends Like these... (10): Play in a game with seven or more players from your friends list.
World Traveler (5): Play a complete game on every map.
Zero-Point Energy (5): Get the Gravity Gun in Black Mesa East.
Zombie Chopper (25): Play through Ravenholm using only the Gravity Gun.
Zombie-que (5): Use flares to light 15 zombies on fire.