Like more than one of them
23 games close to two or more of Heaven's Vault, 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
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
Ravenfield
Garry's Mod, but single-player, and a third of the hours
Loved · 97%Sandbox · FPSAlso like Left 4 Dead 2
Counter-Strike Nexon
Left 4 Dead 2, but free to play, and PvP
Mixed · 67%Zombies · FPSAlso like Garry's Mod
Call of Duty: World at War
Left 4 Dead 2, but set in World War II
Loved · 92%Zombies · FPSAlso like Garry's Mod
R.E.P.O.
Garry's Mod, but a survival horror game, and a quarter of the hours
Loved · 96%Physics · ComedyAlso like Left 4 Dead 2
Inside the Backrooms
Left 4 Dead 2, but a psychological horror game, and a puzzle game
Liked · 80%Survival Horror · Online Co-OpAlso like Heaven's Vault
Insurgency: Sandstorm
Garry's Mod, but military, and half the hours
Liked · 85%FPS · ShooterAlso like Left 4 Dead 2
Deceit
Left 4 Dead 2, but a social deduction game, and your choices matter
Mixed · 79%Zombies · FPSAlso 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
Fallout 3 - Game of the Year Edition
Garry's Mod, but an action RPG, and open world
Liked · 82%Sandbox · FPSAlso like Left 4 Dead 2
Unturned
Left 4 Dead 2, but a survival crafting game
Loved · 91%Zombies · SurvivalAlso like Garry's Mod
PlanetSide 2
Garry's Mod, but free to play, and an MMO
Liked · 80%FPS · ShooterAlso like Left 4 Dead 2
Evolve Stage 2
Left 4 Dead 2, but sci-fi, and more divisive
Mixed · 70%FPS · Team-BasedAlso like Garry's Mod
Halo: The Master Chief Collection
Garry's Mod, but story-rich, and a third of the hours
Loved · 92%FPS · ShooterAlso like Left 4 Dead 2
Content Warning
Garry's Mod, but a horror game, and procedurally generated
Loved · 94%Physics · Online Co-OpAlso like Left 4 Dead 2
Avatar: Frontiers of Pandora
Garry's Mod, but a third of the hours, and more divisive
Mixed · 78%Online Co-Op · ShooterAlso like Left 4 Dead 2
More like Garry's Mod
7 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
Fireworks Mania - An Explosive Simulator
Garry's Mod, but a hobby sim, and a tenth of the hours
Loved · 97%Sandbox · Physics
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.