Complete the following achievements to unlock Xbox Live Gamerscore points.
Achievement
How to unlock
"Radiation Levels Detected"(5 points)
Get throughthe toxic tunnel under City 17 in Half-Life 2.
Acid Reflex (5 points)
Kill an acid antlion worker.
Anchor's Aweigh! (5 points)
Get the airboat.
Aperture Science (40 points)
Earn gold medals on all Portal challenges.
Atomizer (10 points)
Disintegrate 15 soldiers by throwing them into a Combine ball field.
Attica! (5 points)
Destroy the gunship in the hospital attic.
Barnacle Bowling (5 points)
Kill five barnacles with one barrel.
Basic Science (10 points)
Earn bronze medals on all Portal challenges.
Blast from the Past (10 points)
Find the HEV Suit Charger faceplate in Eli's scrapyard.
Bone Breaker (5 points)
Kill 30 enemies with thrown physics objects.
Bug Hunt (10 points)
Use the antlions to kill 50 enemies.
Cache Checker (10 points)
Find every radar cache in chapter Under The Radar.
Camera Shy (5 points)
Detach security cameras from the walls.
Car Crusher (5 points)
Use the cars to squash 15 antlions in Episode One.
Citizen Escort (15 points)
Don't let any citizens die when escorting them to the escape train.
Conservationist (5 points)
Kill five enemies with the same energy ball.
Containment (5 points)
Contain the Citadel core.
Counter-Sniper (5 points)
Kill all of the snipers in City 17.
Cupcake (10 points)
Beat two Portal advanced maps.
Deadly Harvest (5 points)
Kill an enemy by planting a hopper mine.
Dynasty (10 points)
Win 20 games.
Elevator Action (10 points)
Survive long enough to get on the parking garage elevator.
Escape From City 17 (20 points)
Escape City 17 with Alyx.
Fight the Power (10 points)
Shut down the supression device by disabling its generators.
Flamethrower (5 points)
Set five enemies on fire in 30 seconds.
Flushed (5 points)
Kill an enemy with a toilet.
Follow Freeman (10 points)
Gain command of a squad of rebels in the uprising.
Fratricide (5 points)
Do whatever it takes to survive.
Friendly Fire (5 points)
Knock down a turret with another turret.
Fruitcake (20 points)
Beat four Portal advanced maps.
Get Some Grub (20 points)
Squish every antlion grub in Episode Two.
Giant Killer (10 points)
Survive the rooftop strider battle in the ruins of City 17.
Gordon Propelled Rocket (5 points)
Unlock the rocket launcher lambda cache in chapter Under The Radar.
Grave Robber (5 points)
Steal a Zombine's grenade.
Grey Matter (5 points)
Get 25 headshots as a Sniper.
Hack Attack! (5 points)
Kill five enemies with a Manhack.
Hard to Kill (10 points)
Get five kills in a row without dying.
Hardcore (15 points)
Accumulate 1000 total kills.
Head of the Class (5 points)
Play a complete round with every class.
Heartbreaker (10 points)
Complete Portal.
Heavy Weapons (5 points)
Get the airboat's mounted gun.
Hit and Run (5 points)
Run over 20 enemies with the car in Episode Two.
Hot PotatOwned (10 points)
Kill a Combine soldier with his own grenade.
Impenetrable Defense (10 points)
Successfully defend Dustbowl without giving up a capture.
Impossible Defense (30 points)
Successfully defend Gravel Pit without giving up a capture.
Into the Breach (5 points)
Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.
Keep Off the Sand! (20 points)
Cross the antlion beach in chapter Sandtraps without touching the sand.
Lab Rat (5 points)
Acquire the fully powered Aperture Science Handheld Portal Device.
Lambda Locator (15 points)
Find all lambda caches in Half-Life2.
Lightning Offense (10 points)
Win Well in 5 minutes or less.
Little Rocket Man (30 points)
Send the garden gnome into space.
Live Bait (10 points)
Help Alyx snipe 30 enemies in Episode One.
Long Jump (5 points)
Jump 300 feet.
Malcontent (5 points)
Escape the apartment block raid.
Master of Disguise (15 points)
Trick an opposing medic into healing you.
Neighborhood Watch (35 points)
Save all buildings outside the missile silo from destruction.
Nemesis (5 points)
Get five revenge kills.
One Man Army (5 points)
Destroy six gunships in Half-Life2.
OSHA Violation (5 points)
Kill 3 enemies using the crane.
Pacifist (10 points)
Contain the Citadel core without killing any stalkers.
Partygoer (5 points)
Make the correct party escort submission position decision.
Payback (10 points)
Kill a Hunter with its own flechettes.
Pedal to the Metal (5 points)
Beat DOG in a race to the White Forest base.
Pinata Party (5 points)
Find and break every web cache in Episode Two.
Plaza Defender (10 points)
Survive the generator plaza standoff in chapter Anticitizen One.
Powerhouse Offense (5 points)
Win 2Fort with a shutout.
Puttin' On a Clinic (15 points)
Defeat the chopper in Episode Two without any misses.
Relentless Offense (20 points)
Win Hydro without giving up a capture.
Revenge! (10 points)
Destroy the hunter-chopper in Half-Life2.
Rocket Science (20 points)
Earn silver medals on all Portal challenges.
Targetted Advertising (5 points)
Pin a soldier to the billboard in chapter Highway 17.
Team Doctor (5 points)
Accumulate 25000 heal points as a Medic.
Terminal Velocity (5 points)
Fall 30,000 feet.
The One Free Bullet (40 points)
Beat Episode One firing exactly one bullet. Grenade, crowbar, rocket, and Gravgun kills are okay!.
Think Fast! (10 points)
Kill an Elite Soldier with his own energy ball.
Trusty Hardware (5 points)
Get the crowbar.
Turret (5 points)
Accumulate 10 turret kills with a single turret.
Two Points (2 points)
Use DOG's ball to make a basket in Eli's scrapyard.
Vanilla Crazy Cake (30 points)
Beat all six Portal advanced maps.
Vorticough (13 points)
Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Warden Freeman (10 points)
Survive the second turret standoff in Nova Prospekt.
Watch Your Head! (5 points)
Make it to the bottom of the Citadel's main elevator shaft in one piece.
What cat? (5 points)
Break the mini-teleporter in Kleiner's lab.
With Friends Like these.. (10 points)
Play in a game with seven or more players from your friends list.
World Traveler (5 points)
Play a complete game on every map.
Zero-Point Energy (5 points)
Get the Gravity Gun in Black Mesa East.
Zombie Chopper (25 points)
Play through Ravenholm using only the Gravity Gun.
Zombie-que (5 points)
Use flares to light 15 zombies on fire.
Alternate Title Screen (Portal)
Complete the game.
Alternate Title Screen (Portal)
Complete the game.
Box head pictures (Portal)
On the level where you get the companion cube after you run past the energy balls and are in the room with the three elevators, there are two doors leading to a catcher, and a platform that is pushed out of the wall. Walk up to the platform that is pushed out. Crouch behind it and walk through the opening. On the left hand side are a group of pictures of people with boxes for heads and hearts around them.
Breaking locks without bullets
If you are going for the achievement 'one free bullet' and you are unsure of how to brake locks without shooting them. You can use the gravity gun to shoot an explosive barrel or just about any other object at it. Just make sure that you use at least one bullet wether you use it on a lock or just shoot it randomly at the end.
Cheat mode (Half-Life 2)
You can use one of the following cheat codes:
Code
Effect
Press Y, Up, Y, Right, Y, Down, Y, Left, Y, Up during game play
AA
Press Down(3), LB, Down(3), RB, Down(2) during game play
Enemies do not target you
Press Y, B, A, X, RB, Y, X, A, B, RB during game play. Note: This may need to be entered for each weapon
Full ammunition
Press LB, Up, RB, Up, LB(2), Up, RB(2), Up during game play
Invincibility
Press LB, Down, RB, Down, LB(2), Down, RB(2), Down during game play
Kill
Press Left(4), LB, Right(4), RB during game play
Level select
Press Up(3), LB, Up(3), RB, Up(2) during game play
No Clipping mode
Press Up(2), Down(2), Left, Right, Left, Right, B, A during game play to regain 25 points of health
Restore health
Cheat mode (Half-Life 2: Episode One)
You can use one of the following cheat codes:
Code
Effect
Press Left(4), LB, Right(4), RB during game play
Level select
Press Up(2), Down(2), Left, Right, Left, Right, B, A during game play to regain 25 points of health
Restore health
Press Y, B, A, X, RB, Y, X, A, B, RB during game play
Full ammunition
Cheat mode (Half-Life 2: Episode Two)
You can use one of the following cheat codes:
Code
Effect
Press Left(4), LB, Right(4), RB during game play
Level select
Press Y, B, A, X, RB, Y, X, A, B, RB during game play
Full ammunition
Press Up(2), Down(2), Left, Right, Left, Right, B, A during game play to regain 25 points of health
Restore health
Cheat mode (Portal)
You can use one of the following cheat codes:
Code
Effect
Press Down, B, A, B, Y, Down, B, A, B, Y during game play
Create box
Press Up, Y(2), X(2), A(2), B(2), Up during game play
Fire energy ball
Press Up, Y(2), B(2), A(2), X(2), Up during game play
Fire rocket projectile
Press Left(4), LB, Right(4), RB during game play
Level select
Press Y, A, B, A, B, Y(2), A, Left, Right during game play
Portal placement anywhere
Press Up, Left, Down, Right, Up, Left, Down, Right, Y(2) during game play
Portalgun ID 0
Press Up, Left, Down, Right, Up, Left, Down, Right, X(2) during game play
Portalgun ID 1
Press Up, Left, Down, Right, Up, Left, Down, Right, A(2) during game play
Portalgun ID 2
Press Up, Left, Down, Right, Up, Left, Down, Right, B(2) during game play
Portalgun ID 3
Press X, B, LB, RB, Left, Right, LB, RB, LT, RT during game play
Upgrade Portalgun
Easy way to kill hunters
The magnum is very effective on the hunters. Four or five shots will kill them, or if you are at the Strider battle near the end of the game, use the gravity gun to fire the magnuson device at the hunters. This is a one hit K.O.
Faster construction (Team Fortress 2)
As an engineer, do not wait for your building. Simply whack it with the wrench so that it builds faster.
Hidden Left 4 Dead trailer
To get a trailer for the upcoming Valve game Left 4 Dead, wait at the game select screen (the one where you choose between Portal, Team Fortress, or Halflife 2). After a few minutes You will be taken to a demo video of the three orange box games. Wait for the video to end, then wait again. The next time the video comes up, it will be a Left 4 Dead trailer.
Hidden pumpkins (Half-Life 2: Episode Two)
Set the system date to October 31. After you are ambushed by Hunters and Combine at a big house, drive along the road. Near where the supply cache is found you will see an old truck. Go up to it. There will be lots of pumpkins lying on the ground.
New Title Screen (Half-Life 2)
Beat Half-Life 2 to get a new title screen.
Overheating Xbox 360 (Portal)
Play the level where you face off with the laser guided robots. Once you get past the first few robots, you must start dropping the boxes on the robots heads so that they fall over. In the little place that you find the first two boxes, crouch and walk behind where the boxes were. You will find a little room with odd music playing and graffiti on the walls that says things such as "The cake is a liar". There also seems to be an Xbox 360 with a pot inside of it. The Xbox 360 is overheating and boiling the water.
Revolving effect(our mutual fiend)
When you get to the room with eli and kleiner watching judiths message on the level our mutual fiend, get on top of the lockers and empty the cage area until you see a hev plate and metal set of draws.Take them out of the cage and place them on the floor.empty the lockers and place the hev plate against the locker wall (it can face forward or backward as long as its flat against the wall).now place the draws on their back in front of the plate so it blocks all of the locker in front of the hev plate. Close the double locker doorsandwait for the smoke to stop.
now stand in front of the lockers and you will start to spin. Move out of the way to cancel the effect.