Games like TonoTone
Games like TonoTone include Garry's Mod, Slime Rancher, PowerWash Simulator, Totally Accurate Battle Simulator, and BeamNG.drive. We matched them by the tags players give TonoTone on Steam (Casual, Simulation, Sandbox, Cartoony, and Colorful): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Sandbox · Casual · Simulation

Slime Rancher
Shared: Colorful · Singleplayer · Sandbox

PowerWash Simulator
Shared: Casual · Simulation · Sandbox

Totally Accurate Battle Simulator
Shared: Simulation · Sandbox · Singleplayer

BeamNG.drive
Shared: Simulation · Sandbox · Singleplayer

House Flipper
Shared: Simulation · Casual · Sandbox

SPORE™
Shared: Sandbox · Simulation · Casual

Cities: Skylines II
Shared: Simulation · Sandbox · Singleplayer

Cities: Skylines
Shared: Simulation · Sandbox · Singleplayer

Two Point Hospital
Shared: Simulation · Sandbox · Casual

The Sims™ 4
Shared: Simulation · Sandbox · Casual

The Sims™ 3
Shared: Simulation · Sandbox · Casual

Two Point Museum
Shared: Casual · Simulation · Sandbox

Planet Coaster
Shared: Simulation · Sandbox · Singleplayer

Goat Simulator
Shared: Simulation · Sandbox · Casual

Passpartout: The Starving Artist
Shared: Casual · Simulation · Singleplayer

Guilty as Sock!
Shared: Simulation · Casual · Sandbox

Wobbledogs
Shared: Sandbox · Simulation · Colorful

Train Simulator Classic
Shared: Simulation · Casual · Singleplayer

Game Dev Tycoon
Shared: Simulation · Casual · Singleplayer

People Playground
Shared: Sandbox · Simulation · Singleplayer

Townscaper
Shared: Sandbox · Casual · Simulation

SpaceEngine
Shared: Casual · Sandbox · Simulation

The Sims™ 2 Legacy Collection
Shared: Sandbox · Simulation · Casual