Year 1998:
Half-Life
Year 1999:
Half-Life: Opposing Force
Year 2000:
Gunman Chronicles
Year 2001:
Half-Life: Blue Shift
Half-Life: Azure Sheep
Year 2013:
Half-Life: Before
Year 2018:
Halfquake Trilogy
Year 2023:
Half-Life: MMod
Year 2024:
Half-Life: Escape 2.0
Delta Particles