Half-Life 2: Update achievements

Break the mini-teleporter in Kleiner's Lab.

Survive the rooftop strider battle in the ruins of City 17.

Destroy six gunships in Half-Life 2.

Survive the second turret standoff in Nova Prospekt.

Survive the generator plaza standoff in chapter Anticitizen One.

Shut down the supression device by disabling its generators.

Gain command of a squad of rebels in the uprising.

Get through the toxic tunnel under City 17 in Half-Life 2.

Use the Antlions to kill 50 enemies.