Half-Life 2

Contain the Citadel core.

Contain the Citadel core without killing any stalkers.

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

Escape City 17 with Alyx.

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

Survive long enough to get on the parking garage elevator.

Destroy the gunship in the hospital attic.

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

Use the cars to squash 15 antlions in Episode One.

Help Alyx snipe 30 enemies in Episode One.

Defeat both antlion guards outside the White Forest.

Help Griggs and Sheckley hold off the antlion invasion inside the mine shaft.

Save the missile silo from the Combine offensive.

Survive the Hunter ambush with Alyx.

Secure the launch doors on missile silo 2.

Save all buildings outside the missile silo from destruction.

Beat DOG in a race to the White Forest base.

Unlock the rocket launcher lambda cache in chapter Under The Radar.

Survive the ambush at White Forest Inn.

Find and break every web cache in Episode Two.