Like more than one of them
22 games close to two or more of planetarian HD, 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
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
SCP: Secret Laboratory
Left 4 Dead 2, but free to play
Loved · 91%FPS · Survival HorrorAlso like Garry's Mod
Unturned
Left 4 Dead 2, but free to play, and a survival crafting game
Loved · 91%Zombies · SurvivalAlso 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
Ravenfield
Garry's Mod, but single-player, and a third of the hours
Loved · 97%Sandbox · FPSAlso like Left 4 Dead 2
Generation Zero
Left 4 Dead 2, but with base building, and open world
Mixed · 72%FPS · SurvivalAlso like Garry's Mod
Fallout: New Vegas
Garry's Mod, but an action RPG, and post-apocalyptic
Loved · 96%FPS · SandboxAlso like Left 4 Dead 2
7 Days to Die
Garry's Mod, but a base builder, and about survival
Liked · 87%Building · SandboxAlso like Left 4 Dead 2
Codename CURE
Left 4 Dead 2, but military, and a tenth of the hours
Liked · 85%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
Seed of the Dead: Sweet Home
Left 4 Dead 2, but single-player, and solo
Liked · 83%Zombies · FPSAlso like planetarian HD
More like Garry's Mod
4 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 half the hours
Loved · 97%Physics · Sandbox
Fireworks Mania - An Explosive Simulator
Garry's Mod, but a hobby sim, and a tenth of the hours
Loved · 97%Sandbox · Physics
More like Left 4 Dead 2
4 games closest to Left 4 Dead 2 of your picks
Project Zomboid
Left 4 Dead 2, but a survival crafting game, and twice the hours
Loved · 94%Zombies · Survival
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.