Half-Life 2
Cosmic's Progress
Defiant
Unlocked 9 Nov 2013 at 8:26 AM
Submissive
Unlocked 26 Jun 2010 at 3:40 PM
Malcontent
Escape the apartment block raid.
Unlocked 26 Jun 2010 at 3:46 PM
What cat?
Break the mini-teleporter in Kleiner's lab.
Unlocked 9 Nov 2013 at 8:26 AM
Trusty Hardware
Get the crowbar.
Unlocked 26 Jun 2010 at 3:59 PM
Barnacle Bowling
Kill five barnacles with one barrel.
Unlocked 9 Nov 2013 at 8:26 AM
Anchor's Aweigh!
Get the airboat.
Unlocked 9 Nov 2013 at 8:26 AM
Heavy Weapons
Get the airboat's mounted gun.
Unlocked 28 Jan 2013 at 3:17 AM
Vorticough
Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Unlocked 9 Nov 2013 at 8:26 AM
Revenge!
Destroy the hunter-chopper in Half-Life 2.
Unlocked 28 Jan 2013 at 3:38 AM
Blast from the Past
Find the HEV Suit Charger faceplate in Eli's scrapyard.
Unlocked 28 Jan 2013 at 3:57 AM
Zero-Point Energy
Get the Gravity Gun in Black Mesa East.
Unlocked 28 Jan 2013 at 3:58 AM
Two Points
Use DOG's ball to make a basket in Eli's scrapyard.
Unlocked 9 Nov 2013 at 8:26 AM
Zombie Chopper
Play through Ravenholm using only the Gravity Gun.
Unlocked 9 Nov 2013 at 8:26 AM
Hallowed Ground
Unlocked 7 Sep 2013 at 11:46 AM
OSHA Violation
Kill 3 enemies using the crane.
Unlocked 9 Nov 2013 at 8:26 AM
Targetted Advertising
Pin a soldier to the billboard in chapter Highway 17.
Unlocked 9 Nov 2013 at 8:26 AM
Where Cubbage Fears to Tread
Unlocked 9 Nov 2013 at 8:26 AM
One Man Army
Destroy six gunships in Half-Life 2.
Unlocked 9 Nov 2013 at 8:26 AM
Keep Off the Sand!
Cross the antlion beach in chapter Sandtraps without touching the sand.
Unlocked 9 Nov 2013 at 8:26 AM
Bug Hunt
Use the antlions to kill 50 enemies.
Unlocked 9 Nov 2013 at 8:26 AM
Flushed
Kill an enemy with a toilet.
Unlocked 9 Nov 2013 at 8:26 AM
Warden Freeman
Survive the second turret standoff in Nova Prospekt.
Unlocked 9 Nov 2013 at 8:26 AM
Follow Freeman
Gain command of a squad of rebels in the uprising.
Unlocked 9 Nov 2013 at 8:26 AM
Radiation Levels Detected
Get through the toxic tunnel under City 17 in Half-Life 2.
Unlocked 9 Nov 2013 at 8:26 AM
Plaza Defender
Survive the generator plaza standoff in chapter Anticitizen One.
Unlocked 9 Nov 2013 at 8:26 AM
Counter-Sniper
Kill all of the snipers in City 17.
Unlocked 9 Nov 2013 at 8:26 AM
Fight the Power
Shut down the supression device by disabling its generators.
Unlocked 9 Nov 2013 at 8:26 AM
Giant Killer
Survive the rooftop strider battle in the ruins of City 17.
Unlocked 9 Nov 2013 at 8:26 AM
Atomizer
Disintegrate 15 soldiers by throwing them into a Combine ball field.
Unlocked 9 Nov 2013 at 8:26 AM
Singularity Collapse
Unlocked 9 Nov 2013 at 8:26 AM
Lambda Locator
Find all lambda caches in Half-Life 2.
Unlocked 9 Nov 2013 at 8:26 AM
Hack Attack!
Kill five enemies with a Manhack.
Unlocked 9 Nov 2013 at 8:26 AM
Watch Your Head!
Make it to the bottom of the Citadel's main elevator shaft in one piece.
Containment
Contain the Citadel core.
Pacifist
Contain the Citadel core without killing any stalkers.
Car Crusher
Use the cars to squash 15 antlions in Episode One.
Elevator Action
Survive long enough to get on the parking garage elevator.
Live Bait
Help Alyx snipe 30 enemies in Episode One.
Attica!
Destroy the gunship in the hospital attic.
Citizen Escort
Don't let any citizens die when escorting them to the escape train.
Escape From City 17
Escape City 17 with Alyx.
The One Free Bullet
Finish the game firing exactly one bullet. Grenade, crowbar, rocket, and Gravity Gun kills are okay!
Conservationist
Kill five enemies with the same energy ball.
Think Fast!
Kill an Elite Soldier with his own energy ball.
Zombie-que
Use flares to light 15 zombies on fire.
Acid Reflex
Kill an acid antlion worker.
Get Some Grub
Squish every antlion grub in Episode Two.
Piñata Party
Find and break every web cache in Episode Two.
Into the Breach
Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.
Twofer
Defeat both antlion guards outside the White Forest.
Hit and Run
Run over 20 enemies with the car in Episode Two.
Meet the Hunters
Survive the Hunter ambush with Alyx.
Puttin' On a Clinic
Defeat the chopper in Episode Two without any misses.
Gunishment!
Destroy the Combine Autogun in the junkyard.
Cache Checker
Find every radar cache in chapter Under The Radar.
Pedal to the Metal
Beat DOG in a race to the White Forest base.
Gordon Propelled Rocket
Unlock the rocket launcher lambda cache in chapter Under The Radar.
Quiet Mountain Getaway
Survive the ambush at White Forest Inn.
Little Rocket Man
Send the garden gnome into space.
Secondary Silo Secured
Secure the launch doors on missile silo 2.
Neighborhood Watch
Save all buildings outside the missile silo from destruction.
Defense of the Armament
Save the missile silo from the Combine offensive.
Payback
Kill a Hunter with its own flechettes.
Bone Breaker
Kill 30 enemies with thrown physics objects.
Deadly Harvest
Kill an enemy by planting a hopper mine.
Hot Potat0wned
Kill a Combine soldier with his own grenade.
Grave Robber
Steal a Zombine's grenade.
Gnome Alone
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space. If you did not also receive the achievement 'Manufacturing Ascent', Newell has abandoned his plans to shoot Noam Chomsky into space.