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