Steam Achievements
| Unlockable | How to Unlock |
|---|---|
| Acid Reflex | Kill an acid antlion worker. |
| Bone Breaker | Kill 30 enemies with thrown physics objects. |
| Cache Checker | Find every radar cache in chapter Under The Radar. |
| Deadly Harvest | Kill an enemy by planting a hopper mine. |
| Defense of the Armament | Save the missile silo from the Combine offensive. |
| Get Some Grub | Squish every antlion grub in Episode Two. |
| Gordon Propelled Rocket | Unlock the rocket launcher lambda cache in chapter Under The Radar. |
| Grave Robber | Steal a Zombine's grenade. |
| Gunishment! | Destroy the Combine Autogun in the junkyard. |
| Hit and Run | Run over 20 enemies with the car in Episode Two. |
| Hot Potat0wned | Kill a Combine soldier with his own grenade. |
| Into the Breach | Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft. |
| Little Rocket Man | Send the garden gnome into space. |
| Meet the Hunters | Survive the Hunter ambush with Alyx. |
| Neighborhood Watch | Save all buildings outside the missile silo from destruction. |
| Payback | Kill a Hunter with its own flechettes. |
| Pedal to the Metal | Beat DOG in a race to the White Forest base. |
| Pin~ata Party | Find and break every web cache in Episode Two. |
| Puttin' On a Clinic | Defeat the chopper in Episode Two without any misses. |
| Quiet Mountain Getaway | Survive the ambush at White Forest Inn. |
| Secondary Silo Secured | Secure the launch doors on missile silo 2. |
| Twofer | Defeat both antlion guards outside the White Forest. |
