Like more than one of them
29 games close to two or more of Cepheus Protocol, Garry's Mod and Left 4 Dead 2
Killing Floor 2
Much the same as Left 4 Dead 2
Liked · 88%Zombies · FPSAlso like Cepheus Protocol and Garry's Mod
State of Decay 2
Cepheus Protocol, but co-op, and twice the hours
Liked · 83%Zombies · Post-apocalypticAlso like Left 4 Dead 2
Project Zomboid
Cepheus Protocol, but with crafting, and four times the hours
Loved · 94%Zombies · Post-apocalypticAlso like Left 4 Dead 2
Killing Floor
Much the same as Left 4 Dead 2
Loved · 95%Zombies · FPSAlso like Cepheus Protocol and Garry's Mod
Back 4 Blood
Left 4 Dead 2, but more divisive
Mixed · 69%Zombies · FPSAlso like Garry's Mod and Cepheus Protocol
No One Survived
Cepheus Protocol, but with crafting, and co-op
Divisive · 64%Zombies · Post-apocalypticAlso like Left 4 Dead 2 and Garry's Mod
State of Decay
Cepheus Protocol, but third-person
Liked · 85%Zombies · Post-apocalypticAlso like Left 4 Dead 2
GTFO
Left 4 Dead 2, but harder, and half the hours
Liked · 84%FPS · ZombiesAlso like Garry's Mod and Cepheus Protocol
Counter-Strike Nexon
Left 4 Dead 2, but free to play, and PvP
Mixed · 67%Zombies · FPSAlso like Garry's Mod and Cepheus Protocol
Zombie Panic! Source
Left 4 Dead 2, but free to play, and half the hours
Liked · 85%Zombies · FPSAlso like Cepheus Protocol and Garry's Mod
Dead Island Definitive Edition
Left 4 Dead 2, but an action RPG, and open world
Liked · 82%Zombies · SurvivalAlso like Cepheus Protocol
Ravenfield
Garry's Mod, but single-player, and a third of the hours
Loved · 97%Sandbox · FPSAlso like Cepheus Protocol and Left 4 Dead 2
Space Engineers
Garry's Mod, but a survival crafting game, and with base building
Liked · 89%Building · SandboxAlso like Cepheus Protocol
VEIN
Cepheus Protocol, but co-op, and with crafting
Liked · 87%Zombies · Post-apocalypticAlso 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
Blockland
Garry's Mod, but open world, and a quarter of the hours
Mixed · 74%Building · SandboxAlso like Cepheus Protocol and Left 4 Dead 2
World War Z
Left 4 Dead 2, but more divisive
Liked · 82%Zombies · Online Co-OpAlso like Cepheus Protocol and Garry's Mod
Lambda Wars
Cepheus Protocol, but free to play, and sci-fi
Loved · 92%RTS · ZombiesAlso like Left 4 Dead 2 and Garry's Mod
Dead Rising 2: Off the Record
Cepheus Protocol, but a hack and slash game, and funny
Mixed · 77%Zombies · SandboxAlso like Left 4 Dead 2 and Garry's Mod
Arma 3
Garry's Mod, but a wargame, and military
Loved · 90%Sandbox · FPSAlso like Cepheus Protocol and Left 4 Dead 2
Dead Rising 3
Cepheus Protocol, but a hack and slash game, and funny
Mixed · 77%Zombies · SurvivalAlso like Left 4 Dead 2 and Garry's Mod
Propagation VR
Left 4 Dead 2, but in VR, and a tenth of the hours
Loved · 94%Zombies · FPSAlso like Cepheus Protocol
Codename CURE
Cepheus Protocol, but a first-person shooter, and a third of the hours
Liked · 85%Zombies · Post-apocalypticAlso like Left 4 Dead 2 and Garry's Mod
Cry of Fear
Left 4 Dead 2, but a psychological horror game, and a third of the hours
Liked · 89%Zombies · Survival HorrorAlso like Cepheus Protocol
Pavlov VR
Left 4 Dead 2, but in VR, and military
Liked · 88%Zombies · FPSAlso like Garry's Mod and Cepheus Protocol
Core Keeper
Cepheus Protocol, but pixel art, and three times the hours
Loved · 93%Survival · SandboxAlso like Garry's Mod
Survarium
Cepheus Protocol, but free to play, and a first-person shooter
Divisive · 55%Post-apocalyptic · ZombiesAlso like Left 4 Dead 2 and Garry's Mod
Plague Inc: Evolved
Much the same as Cepheus Protocol
Loved · 94%Zombies · Post-apocalypticAlso like Left 4 Dead 2
More like Cepheus Protocol
1 games closest to Cepheus Protocol of your picks
Fallout Shelter
Cepheus Protocol, but free to play, and a colony sim
Liked · 88%Post-apocalyptic · 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.