Games like Smash Room
Games like Smash Room include Garry's Mod, BONEWORKS, People Playground, Goat Simulator, and Teardown. We matched them by the tags players give Smash Room on Steam (Casual, Action, Sandbox, Hack and Slash, and Physics): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Sandbox · Casual · Physics

BONEWORKS
Shared: Action · VR · Sandbox

People Playground
Shared: Sandbox · Physics · Singleplayer

Goat Simulator
Shared: Sandbox · Casual · Physics

Teardown
Shared: Sandbox · Physics · Destruction

Just Cause™ 3
Shared: Action · Sandbox · Singleplayer

BONELAB
Shared: Sandbox · VR · Action

BeamNG.drive
Shared: Physics · Sandbox · Destruction

Hot Dogs, Horseshoes & Hand Grenades
Shared: Sandbox · VR · Physics

Just Cause 4 Reloaded
Shared: Action · Sandbox · Singleplayer

Blade and Sorcery
Shared: VR · Sandbox · Action

HITMAN World of Assassination
Shared: Action · VR · Sandbox

Turbo Dismount™
Shared: Physics · Action · Sandbox

Fireworks Mania - An Explosive Simulator
Shared: Sandbox · Singleplayer · Physics

Hard Bullet
Shared: Action · Sandbox · VR

Just Cause 2
Shared: Action · Sandbox · Singleplayer

Brick Rigs
Shared: Sandbox · Physics · Destruction

Gang Beasts
Shared: Action · Casual · Physics

STANDBOX
Shared: Sandbox · Action · Casual

NightClub Simulator
Shared: Action · VR · Sandbox

We Who Are About To Die
Shared: Action · Physics · Sandbox

BRUTALISTICK VR
Shared: Action · VR · Sandbox

Totally Accurate Battle Simulator
Shared: Sandbox · Physics · Singleplayer

鬼谷八荒 Tale of Immortal
Shared: Sandbox · Singleplayer · Action