Contain the Citadel core

Make it to the bottom of the Citadel's main elevator shaft in one piece

Survive long enough to get on the parking garage elevator.

Destroy the gunship in the hospital attic.

Help Alyx snipe 30 enemies in Episode One.

Escape City 17 with Alyx.

Don't let any citizens die when escorting them to the escape train.

Kill an Elite Soldier with his own energy ball.

Contain the Citadel core without killing any stalkers.

Use the cars to squash 15 antlions in Episode One.

Kill five enemies with the same energy ball.

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

Use flares to light 15 zombies on fire.