Games like Lade's Sandbox
Games like Lade's Sandbox include Garry's Mod, Stardew Valley, House Flipper, Space Engineers, and Paralives. We matched them by the tags players give Lade's Sandbox on Steam (Casual, Voxel, Simulation, Relaxing, and Building): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Sandbox · Casual · Building

Stardew Valley
Shared: Relaxing · Simulation · Sandbox

House Flipper
Shared: Simulation · Casual · Building

Space Engineers
Shared: Building · Sandbox · Simulation

Paralives
Shared: Simulation · Building · Casual

My Time at Portia
Shared: Casual · Simulation · Open World

Scrap Mechanic
Shared: Building · Sandbox · Physics

Kerbal Space Program
Shared: Simulation · Sandbox · Physics

Townscaper
Shared: Relaxing · Casual · Building

Goat Simulator
Shared: Simulation · Casual · Sandbox

Train Simulator Classic
Shared: Simulation · Casual · Relaxing

Potion Craft: Alchemist Simulator
Shared: Simulation · Relaxing · Crafting

Cities: Skylines II
Shared: Simulation · Building · Sandbox

The Sims™ 4
Shared: Simulation · Building · Casual

Empyrion - Galactic Survival
Shared: Simulation · Building · Voxel

People Playground
Shared: Sandbox · Physics · Simulation

Planet Coaster
Shared: Simulation · Building · Relaxing

Poly Bridge
Shared: Simulation · Building · Physics

Universe Sandbox
Shared: Simulation · Sandbox · Physics

Tiny Glade
Shared: Relaxing · Building · Casual

Aviassembly
Shared: Building · Physics · Sandbox

Brick Rigs
Shared: Sandbox · Building · Simulation

My Dream Setup
Shared: Simulation · Relaxing · Building

BeamNG.drive
Shared: Simulation · Physics · Sandbox