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