Atomizer (10G)
Disintegrate 15 soldiers by throwing them into a Combine ball field.
Attica! (5G)
Destroy the gunship in the hospital attic.
Bone Breaker (5G)
Kill 30 enemies with thrown physics objects.
Bug Hunt (10G)
Use the antlions to kill 50 enemies.
Cache Checker (10G)
Find every radar cache in chapter Under The Radar.
Camera Shy (5G)
Detach security cameras from the walls.
Car Crusher (5G)
Use the cars to squash 15 antlions in Episode One.
Citizen Escort (15G)
Don't let any citizens die when escorting them to the escape train.
Cupcake (10G)
Beat two Portal advanced maps.
Elevator Action (10G)
Survive long enough to get on the parking garage elevator.
Fight the Power (10G)
Shut down the supression device by disabling its generators.
Flushed (5G)
Kill an enemy with a toilet.
Follow Freeman (10G)
Gain command of a squad of rebels in the uprising.
Fruitcake (20G)
Beat four Portal advanced maps.
Giant Killer (10G)
Survive the rooftop strider battle in the ruins of City 17.
Hardcore (15G)
Accumulate 1000 total kills.
Hit and Run (5G)
Run over 20 enemies with the car in Episode Two.
Into the Breach (5G)
Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.
Keep Off the Sand! (20G)
Cross the antlion beach in chapter Sandtraps without touching the sand.
Lab Rat (5G)
Acquire the fully powered Aperture Science Handheld Portal Device.
Live Bait (10G)
Help Alyx snipe 30 enemies in Episode One.
Nemesis (5G)
Get five revenge kills.
Pacifist (10G)
Contain the Citadel core without killing any stalkers.
Partygoer (5G)
Make the correct party escort submission position decision.
Payback (10G)
Kill a Hunter with its own flechettes.
Pinata Party (5G)
Find and break every web cache in Episode Two.
Plaza Defender (10G)
Survive the generator plaza standoff in chapter Anticitizen One.
Revenge! (10G)
Destroy the hunter-chopper in Half-Life 2.
Team Doctor (5G)
Accumulate 25000 heal points as a Medic.
The One Free Bullet (40G)
Beat Episode One firing exactly one bullet. Grenade, crowbar, rocket, and...
Think Fast! (10G)
Kill an Elite Soldier with his own energy ball.
Turret (5G)
Accumulate 10 turret kills with a single turret.
Two Points (2G)
Use DOG's ball to make a basket in Eli's scrapyard.
Vorticough (13G)
Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Warden Freeman (10G)
Survive the second turret standoff in Nova Prospekt.
Watch Your Head! (5G)
Make it to the bottom of the Citadel's main elevator shaft in one piece.
What cat? (5G)
Break the mini-teleporter in Kleiner's lab.
Zombie Chopper (25G)
Play through Ravenholm using only the Gravity Gun.
Zombie-que (5G)
Use flares to light 15 zombies on fire.