Half-Life 2 achievements

Squish every antlion grub in Episode Two.

Save all buildings outside the missile silo from destruction.

Find and break every web cache in Episode Two.

Kill a Combine soldier with his own grenade.

Send the garden gnome into space.

Kill a Hunter with its own flechettes.

Finish the game firing exactly one bullet. Grenade, crowbar, rocket, and Gravity Gun kills are okay!

Defeat the chopper in Episode Two without any misses.

Kill five enemies with the same energy ball.

Use flares to light 15 zombies on fire.

Run over 20 enemies with the car in Episode Two.

Contain the Citadel core without killing any stalkers.