Like more than one of them
24 games close to two or more of Quake III Arena, Garry's Mod and Left 4 Dead 2
Splitgate
Quake III Arena, but free to play, and PvP
Loved · 91%Arena Shooter · FPSAlso like Garry's Mod and Left 4 Dead 2
SCP: Secret Laboratory
Left 4 Dead 2, but free to play
Loved · 91%FPS · Survival HorrorAlso like Garry's Mod
Half-Life 2: Deathmatch
Quake III Arena, but physics-driven, and co-op
Loved · 91%Arena Shooter · CompetitiveAlso like Garry's Mod
Counter-Strike: Source
Quake III Arena, but team-based, and four times the hours
Loved · 96%Competitive · FPSAlso like Garry's Mod and Left 4 Dead 2
No More Room in Hell
Left 4 Dead 2, but free to play, and half the hours
Loved · 90%Zombies · SurvivalAlso like Garry's Mod
Counter-Strike 2
Quake III Arena, but free to play, and 49 times the hours
Liked · 86%Competitive · FPSAlso like Garry's Mod and Left 4 Dead 2
Ravenfield
Garry's Mod, but single-player, and a third of the hours
Loved · 97%Sandbox · FPSAlso like Left 4 Dead 2
Serious Sam 4
Quake III Arena, but twice the hours, and more divisive
Liked · 83%FPS · Arena ShooterAlso like Garry's Mod and Left 4 Dead 2
Shotgun Farmers
Garry's Mod, but team-based, and a tenth of the hours
Loved · 93%FPS · ShooterAlso like Quake III Arena and Left 4 Dead 2
Serious Sam HD: The First Encounter
Garry's Mod, but a boomer shooter, and a tenth of the hours
Loved · 93%FPS · ComedyAlso like Quake III Arena and Left 4 Dead 2
THE FINALS
Quake III Arena, but free to play, and with destruction
Mixed · 78%Arena Shooter · CompetitiveAlso like Left 4 Dead 2 and Garry's Mod
Sven Co-op
Left 4 Dead 2, but free to play, and retro
Loved · 94%FPS · Team-BasedAlso like Garry's Mod and Quake III Arena
Call of Duty: World at War
Left 4 Dead 2, but set in World War II
Loved · 92%Zombies · FPSAlso like Garry's Mod
Call of Duty: Black Ops II
Left 4 Dead 2, but a quarter of the hours, and more divisive
Liked · 86%FPS · Team-BasedAlso like Garry's Mod
Zombie Panic! Source
Left 4 Dead 2, but half the hours, and more divisive
Liked · 85%Zombies · FPSAlso like Garry's Mod
Insurgency: Sandstorm
Garry's Mod, but military, and half the hours
Liked · 85%FPS · ShooterAlso like Left 4 Dead 2
Tom Clancy's Rainbow Six Siege
Garry's Mod, but free to play, and competitive
Liked · 82%FPS · PvPAlso like Quake III Arena and Left 4 Dead 2
More like Quake III Arena
4 games closest to Quake III Arena of your picks
Unreal Tournament: Game of the Year Edition
Much the same as Quake III Arena
Loved · 97%Arena Shooter · FPS
Deathmatch Classic
Quake III Arena, but a quarter of the hours, and more divisive
Liked · 83%Arena Shooter · FPS
More like Garry's Mod
2 games closest to Garry's Mod of your picks
Scrap Mechanic
Garry's Mod, but a survival crafting game, and with base building
Loved · 92%Building · Physics
Hot Dogs, Horseshoes & Hand Grenades
Garry's Mod, but in VR, and single-player
Loved · 97%Physics · Sandbox
How this list is made
Each game is measured against each of your picks the way a games-like list measures it: the Steam community tags, Steam genres and IGDB themes they share, each counting for more the fewer games carry it. A game's place is how alike it is to your picks together, as a share of each pick's best match, so one alike to two of them comes before one alike to just one. It must be close to at least one of them, as close as it would have to be on that game's own list.
None of your picks is on the list, nor a second release of one, nor a game of their own series. Up to 30 games are shown. Under each name, the kinds it shares with the pick it is closest to, and how it differs from that pick.