Games like Stonescape
Games like Stonescape include Garry's Mod, The Long Dark, The Forest, Rust, and Scrap Mechanic. We matched them by the tags players give Stonescape on Steam (Casual, Sandbox, Hack and Slash, 3D, and First-Person): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Sandbox · Casual · First-Person

The Long Dark
Shared: Atmospheric · First-Person · Open World

The Forest
Shared: Open World · First-Person · Sandbox

Rust
Shared: Sandbox · Open World · First-Person

Scrap Mechanic
Shared: Sandbox · Open World · Building

Sons Of The Forest
Shared: Open World · First-Person · Survival

Fireworks Mania - An Explosive Simulator
Shared: Sandbox · 3D · First-Person

PowerWash Simulator
Shared: Casual · Sandbox · First-Person

Slime Rancher
Shared: First-Person · Sandbox · Casual

SpaceEngine
Shared: Casual · Sandbox · Open World

Slime Rancher 2
Shared: First-Person · Casual · Open World

PC Building Simulator
Shared: Sandbox · First-Person · 3D

No Man's Sky
Shared: Open World · Sandbox · First-Person

Dystopika
Shared: Sandbox · Dystopian · Atmospheric

Fallout 4
Shared: Open World · Atmospheric · First-Person

House Flipper
Shared: Sandbox · Casual · Singleplayer

Space Engineers
Shared: Sandbox · Building · Open World

Terraria
Shared: Sandbox · Survival · Open World

SUMMERHOUSE
Shared: Sandbox · Casual · Atmospheric

Breathedge
Shared: Sandbox · First-Person · Singleplayer

DrainSim
Shared: Casual · Sandbox · First-Person

We Happy Few
Shared: First-Person · Open World · Dystopian

Goat Simulator
Shared: Sandbox · Casual · Open World

Project Zomboid
Shared: Sandbox · Open World · Survival