Multiplayer first person shooter games for PC/Windows with online support

Left 4 Dead

Players: 2 local, 4 online

Warhammer: Vermintide 2

Players: 0 local, 4 online

Far Cry 6

Players: 0 local, 2 online

Unreal Tournament 3

Players: 0 local, 4 online

Serious Sam: The First Encounter

Players: 4 local, 16 online

DOOM 3: OpenCoop (Mod)

Players: 0 local, 4 online

Call of Duty: World at War

Players: 0 local, 4 online

Codename: Outbreak

Players: 0 local, 2 online

The Goatman

Players: 0 local, 3 online

Halo Infinite

Players: 0 local, 4 online

Superbugs: Awaken

Players: 0 local, 2 online

ORION: Prelude

Players: 0 local, 5 online

Borderlands: The Pre-Sequel

Players: 0 local, 4 online

Killing Floor 2

Players: 0 local, 6 online

Verdun

Players: 0 local, 4 online

Shadow Warrior (1997)

Players: 0 local, 2 online

Back 4 Blood

Players: 0 local, 4 online

Unfortunate Spacemen

Players: 0 local, 10 online

Halo: The Master Chief Collection

Players: 0 local, 4 online

Serious Sam 2

Players: 4 local, 6 online

Quake

Players: 0 local, 16 online

Shadow Warrior 2

Players: 0 local, 4 online

Serious Sam: The Second Encounter

Players: 0 local, 16 online

PAYDAY 2

Players: 0 local, 4 online

Conflict: Denied Ops

Players: 0 local, 2 online