Defiant
Giant Killer
Survive the rooftop strider battle in the ruins of City 17.
Hallowed Ground
Keep Off the Sand!
Cross the antlion beach in chapter Sandtraps without touching the sand.
Singularity Collapse
Plaza Defender
Survive the generator plaza standoff in chapter Anticitizen One.
Zombie Chopper
Play through Ravenholm using only the Gravity Gun.
Fight the Power
Shut down the supression device by disabling its generators.
Radiation Levels Detected
Get through the toxic tunnel under City 17 in Half-Life 2.
Warden Freeman
Survive the second turret standoff in Nova Prospekt.
What cat?
Break the mini-teleporter in Kleiner's Lab.
Atomizer
Disintegrate 15 soldiers by throwing them into a Combine ball field.
Malcontent
Escape the apartment block raid.
Lambda Locator
Find all lambda caches in Half-Life 2.
Blast from the Past
Find the HEV Suit Charger faceplate in Eli's scrapyard.
Vorticough
Discover the hidden singing vortigaunt cave in chapter Water Hazard.
Follow Freeman
Gain command of a squad of rebels in the uprising.
Anchor's Aweigh!
Get the airboat.
Heavy Weapons
Get the airboat's mounted gun.
Trusty Hardware
Get the crowbar.
Zero-Point Energy
Get the Gravity Gun in Black Mesa East.
Counter-Sniper
Kill all of the snipers in City 17.
Barnacle Bowling
Kill five barnacles with one explosive barrel.
Revenge!
Destroy the Hunter-Chopper.
Bug Hunt
Use the Antlions to kill 50 enemies.
OSHA Violation
Kill 3 enemies using the crane.
Flushed
Kill an enemy with a toilet.
Where Cubbage Fears to Tread
Two Points
Use Dog's ball to make a basket in the scrapyard.
Targeted Advertising
Pin a soldier to the billboard in the chapter Highway 17.
Submissive
One Man Army
Destroy six gunships in Half-Life 2.
Hack Attack!
Kill five enemies with a Manhack.