There are a maximum of 33 Half-Life 2 achievements worth 511
5,397 tracked gamers have this game, 953 have completed it (17.66%)
Survive the generator plaza standoff in chapter Anticitizen One.
Unlocked by 2,338 tracked gamers (43% - TSA Ratio = 1.51)
Do you have a question about this achievement? Please post it in the Half-Life 2 Forum