Like more than one of them
28 games close to two or more of Universe Sandbox Legacy, Garry's Mod and Left 4 Dead 2
Kerbal Space Program
Universe Sandbox Legacy, but 20 times the hours, and even better loved
Loved · 96%Science · SpaceAlso like Garry's Mod
Space Engineers
Garry's Mod, but a survival crafting game, and with base building
Liked · 89%Building · SandboxAlso like Universe Sandbox Legacy
Fireworks Mania - An Explosive Simulator
Garry's Mod, but a hobby sim, and a tenth of the hours
Loved · 97%Sandbox · PhysicsAlso like Universe Sandbox Legacy
People Playground
Garry's Mod, but single-player, and 2D
Loved · 98%Physics · SandboxAlso like Universe Sandbox Legacy
Ravenfield
Garry's Mod, but military, and a third of the hours
Loved · 97%Sandbox · FPSAlso like Left 4 Dead 2
BONEWORKS
Garry's Mod, but in VR, and a quarter of the hours
Loved · 92%Physics · SandboxAlso like Universe Sandbox Legacy
Goat Simulator 3
Garry's Mod, but 3D, and a fifth of the hours
Loved · 98%Physics · SandboxAlso like Universe Sandbox Legacy
Just Cause 2
Garry's Mod, but a third-person shooter, and third-person
Loved · 91%Sandbox · PhysicsAlso like Universe Sandbox Legacy
SCP: Secret Laboratory
Left 4 Dead 2, but free to play
Loved · 91%FPS · Survival HorrorAlso like Garry's Mod
Kerbal Space Program 2
Universe Sandbox Legacy, but harder, and three times the hours
Disliked · 26%Science · SpaceAlso 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
Brick Rigs
Garry's Mod, but with destruction, and open world
Loved · 95%Sandbox · PhysicsAlso like Universe Sandbox Legacy
Counter-Strike Nexon
Left 4 Dead 2, but free to play, and PvP
Mixed · 67%Zombies · FPSAlso like Garry's Mod
Space Engineers 2
Universe Sandbox Legacy, but a survival game, and open world
Mixed · 75%Space · ScienceAlso like Garry's Mod
Totally Accurate Battlegrounds
Garry's Mod, but free to play, and a battle royale
Liked · 88%Physics · SandboxAlso like Left 4 Dead 2
Fun with Ragdolls: The Game
Garry's Mod, but 3D, and a tenth of the hours
Liked · 88%Physics · SandboxAlso like Universe Sandbox Legacy
Just Cause 3
Garry's Mod, but a third-person shooter, and a third of the hours
Liked · 84%Physics · SandboxAlso like Universe Sandbox Legacy
Mutilate-a-Doll 2
Garry's Mod, but gorier, and single-player
Loved · 93%Physics · SandboxAlso like Universe Sandbox Legacy
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
Unturned
Left 4 Dead 2, but 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
More like Garry's Mod
2 games closest to Garry's Mod of your picks
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.