Games like Domino Sandbox
Games like Domino Sandbox include Garry's Mod, Planet Coaster, Townscaper, House Flipper, and My Dream Setup. We matched them by the tags players give Domino Sandbox on Steam (Building, Sandbox, Minimalist, Relaxing, and Simulation): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Sandbox · Building · Physics

Planet Coaster
Shared: Building · Sandbox · Simulation

Townscaper
Shared: Building · Sandbox · Relaxing

House Flipper
Shared: Simulation · Building · Sandbox

My Dream Setup
Shared: Building · Relaxing · Sandbox

The Sims™ 4
Shared: Building · Simulation · Sandbox

Poly Bridge
Shared: Building · Simulation · Sandbox

Space Engineers
Shared: Building · Sandbox · Simulation

People Playground
Shared: Sandbox · Physics · Building

PC Building Simulator
Shared: Building · Simulation · Sandbox

Stardew Valley
Shared: Relaxing · Sandbox · Simulation

Scrap Mechanic
Shared: Building · Sandbox · Physics

Hozy
Shared: Relaxing · Sandbox · Building

Kerbal Space Program
Shared: Sandbox · Simulation · Building

Cities: Skylines II
Shared: Building · Sandbox · Simulation

Brick Rigs
Shared: Sandbox · Building · Physics

Cities: Skylines
Shared: Building · Simulation · Sandbox

Planet Coaster 2
Shared: Sandbox · Building · Simulation

Poly Bridge 2
Shared: Building · Sandbox · Physics

Aviassembly
Shared: Building · Sandbox · Physics

Totally Accurate Battle Simulator
Shared: Sandbox · Simulation · Physics

Mini Motorways
Shared: Simulation · Minimalist · Relaxing

PowerWash Simulator
Shared: Relaxing · Simulation · Sandbox

Tiny Glade
Shared: Building · Sandbox · Relaxing