Games like Monster Museum
Games like Monster Museum include Slime Rancher, Slime Rancher 2, Fallout 4, PowerWash Simulator, and Garry's Mod. We matched them by the tags players give Monster Museum on Steam (Creature Collector, First-Person, Exploration, Singleplayer, and Open World): closest matches first, and among equally close ones the better-known games.
Slime Rancher
Shared: Exploration · Singleplayer · First-Person
Slime Rancher 2
Shared: Singleplayer · First-Person · Creature Collector
Fallout 4
Shared: Open World · Exploration · Singleplayer
PowerWash Simulator
Shared: First-Person · Casual · Relaxing
Garry's Mod
Shared: Sandbox · First-Person · Singleplayer
Big Walk
Shared: Exploration · Open World · First-Person
The Long Dark
Shared: Exploration · Open World · First-Person
No Man's Sky
Shared: Open World · Exploration · First-Person
Bugsnax
Shared: Creature Collector · Singleplayer · First-Person
Fireworks Mania - An Explosive Simulator
Shared: Singleplayer · Sandbox · Exploration
Fallout: New Vegas
Shared: Open World · Singleplayer · Exploration
The Witness
Shared: First-Person · Exploration · Singleplayer
The Elder Scrolls IV: Oblivion® Game of the Year Edition (2009)
Shared: Open World · Singleplayer · First-Person
LEGO® Worlds
Shared: Open World · Exploration · Sandbox
Grand Theft Auto V Legacy
Shared: Open World · First-Person · Singleplayer
Goat Simulator 3
Shared: Exploration · Sandbox · Open World
SPORE™
Shared: Open World · Exploration · Sandbox
Internet Cafe Simulator 2
Shared: Exploration · First-Person · Sandbox
Starfield
Shared: Singleplayer · Open World · Exploration
Bloons TD 6
Shared: Singleplayer · Family Friendly · Sandbox
The Elder Scrolls IV: Oblivion Remastered
Shared: Open World · Singleplayer · Exploration
Cyberpunk 2077
Shared: Open World · Singleplayer · First-Person
POSTAL 2
Shared: First-Person · Open World · Sandbox
Subnautica
Shared: Exploration · Open World · Singleplayer