Half-Life
1.2 hrs last two weeks / 124.7 hrs on record
Counter-Strike: Source
Half-Life 2
11.7 hrs on record
Half-Life 2: Deathmatch
0.9 hrs on record
Half-Life 2: Lost Coast
Half-Life: Blue Shift
Half-Life: Opposing Force
Half-Life: Source
Half-Life Deathmatch: Source
0.5 hrs on record
Source SDK
