Use the Co-op overload to kill 60 enemies.

Destroy all of the towers in Gorthon Crater.

Defeat 1000 enemies.

Clear the game in single player on the “Supreme Master” difficulty setting.

Save a turret from redemption

Make a break for it

Complete Test Chamber 10 in 70 seconds

Place a cube on a button without touching the cube

Use an Aerial Faith Plate to launch a turret

Reunite with GLaDOS

称号「お宅訪問」を獲得した

Kill a zoomed-in enemy sniper with a sniper rifle of your own