Games like UFOs On Stream
Games like UFOs On Stream include Garry's Mod, People Playground, Totally Accurate Battle Simulator, Goat Simulator, and Teardown. We matched them by the tags players give UFOs On Stream on Steam (Sandbox, Casual, Physics, Aliens, and Asynchronous Multiplayer): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Sandbox · Physics · Casual

People Playground
Shared: Sandbox · Physics · Singleplayer

Totally Accurate Battle Simulator
Shared: Sandbox · Physics · Simulation

Goat Simulator
Shared: Sandbox · Physics · Casual

Teardown
Shared: Sandbox · Physics · Singleplayer

BeamNG.drive
Shared: Physics · Sandbox · Simulation

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

Kerbal Space Program
Shared: Sandbox · Physics · Simulation

Hardspace: Shipbreaker
Shared: Physics · Sci-fi · Sandbox

Goat Simulator 3
Shared: Sandbox · Physics · Casual

BONEWORKS
Shared: Physics · Sandbox · Singleplayer

House Flipper
Shared: Sandbox · Singleplayer · Casual

CarX Drift Racing Online
Shared: Sandbox · Physics · Simulation

Uncrashed : FPV Drone Simulator
Shared: Physics · Simulation · Singleplayer

DrainSim
Shared: Casual · Sandbox · Physics

SpaceEngine
Shared: Casual · Sandbox · Sci-fi

Turbo Dismount™
Shared: Physics · Sandbox · Singleplayer

SPORE™
Shared: Sandbox · Casual · Simulation

PowerWash Simulator
Shared: Casual · Sandbox · Simulation

Universe Sandbox
Shared: Sandbox · Physics · Casual

GoreBox
Shared: Sandbox · Physics · 3D

Fun with Ragdolls: The Game
Shared: Sandbox · Physics · Simulation

Space Engineers
Shared: Sandbox · Physics · Simulation

Cooking Simulator
Shared: Sandbox · Physics · Singleplayer