Hit and Run
Not unlocked yetRun over 20 enemies with the car in Episode Two.
Payback
Not unlocked yetKill a Hunter with its own flechettes.
Acid Reflex
Not unlocked yetKill an acid antlion worker.
Little Rocket Man
Not unlocked yetSend the garden gnome into space.
Grave Robber
Not unlocked yetSteal a Zombine's grenade.
Zombie-que
Not unlocked yetUse flares to light 15 zombies on fire.
Gnome Alone
Not unlocked yetIf 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.
Giant Killer
Not unlocked yetSurvive the rooftop strider battle in the ruins of City 17.
Hallowed Ground
Not unlocked yetEscort Gregori safely through the church cemetery.
Keep Off the Sand!
Not unlocked yetCross the antlion beach in chapter Sandtraps without touching the sand.
Singularity Collapse
Not unlocked yetDestroy the Citadel's reactor core.
Plaza Defender
Not unlocked yetSurvive the generator plaza standoff in chapter Anticitizen One.
Zombie Chopper
Not unlocked yetPlay through Ravenholm using only the Gravity Gun.
Fight the Power
Not unlocked yetShut down the supression device by disabling its generators.
Radiation Levels Detected
Not unlocked yetGet through the toxic tunnel under City 17 in Half-Life 2.
Warden Freeman
Not unlocked yetSurvive the second turret standoff in Nova Prospekt.
What cat?
Not unlocked yetBreak the mini-teleporter in Kleiner's lab.
Atomizer
Not unlocked yetDisintegrate 15 soldiers by throwing them into a Combine ball field.
Malcontent
Not unlocked yetEscape the apartment block raid.
Lambda Locator
Not unlocked yetFind all lambda caches in Half-Life 2.
Blast from the Past
Not unlocked yetFind the HEV Suit Charger faceplate in Eli's scrapyard.
Vorticough
Not unlocked yetDiscover the hidden singing vortigaunt cave in chapter Water Hazard.
Follow Freeman
Not unlocked yetGain command of a squad of rebels in the uprising.
Anchor's Aweigh!
Not unlocked yetGet the airboat.