Achieved | Achievement | % of players | Unlock date |
|---|---|---|---|
 | Acid Reflex Kill an acid antlion worker. | 98.63% | |
 | Into the Breach Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft. | 90.21% | |
 | Twofer Defeat both antlion guards outside the White Forest. | 82.21% | |
 | Meet the Hunters Survive the Hunter ambush with Alyx. | 79.76% | |
 | Gunishment! Destroy the Combine Autogun in the junkyard. | 77.84% | |
 | Quiet Mountain Getaway Survive the ambush at White Forest Inn. | 76.77% | |
 | Secondary Silo Secured Secure the launch doors on missile silo 2. | 75.39% | |
 | Deadly Harvest Kill an enemy by planting a hopper mine. | 73.89% | |
 | Defense of the Armament Save the missile silo from the Combine offensive. | 64.94% | |
 | Gordon Propelled Rocket Unlock the rocket launcher lambda cache in chapter Under The Radar. | 63.87% | |
 | Cache Checker Find every radar cache in chapter Under The Radar. | 49.16% | |
 | Grave Robber Steal a Zombine's grenade. | 38.81% | |
 | Hit and Run Run over 20 enemies with the car in Episode Two. | 38.39% | |
 | Pedal to the Metal Beat DOG in a race to the White Forest base. | 38.39% | |
 | Bone Breaker Kill 30 enemies with thrown physics objects. | 23.56% | |
 | Payback Kill a Hunter with its own flechettes. | 21.22% | |
 | Piñata Party Find and break every web cache in Episode Two. | 14.18% | |
 | Puttin' On a Clinic Defeat the chopper in Episode Two without any misses. | 11.09% | |
 | Hot Potat0wned Kill a Combine soldier with his own grenade. | 9.17% | |
 | Little Rocket Man Send the garden gnome into space. | 7.36% | |
 | Neighborhood Watch Save all buildings outside the missile silo from destruction. | 6.72% | |
 | Get Some Grub Squish every antlion grub in Episode Two. | 5.44% |