Games like Meltopia
Games like Meltopia include A Game About Digging A Hole, Slime Rancher, Garry's Mod, No Man's Sky, and PEAK. We matched them by the tags players give Meltopia on Steam (Exploration, Mining, Sandbox, Underground, and Snow): closest matches first, and among equally close ones the better-known games.

A Game About Digging A Hole
Shared: Exploration · Mining · Sandbox

Slime Rancher
Shared: Exploration · Sandbox · First-Person

Garry's Mod
Shared: Sandbox · Casual · Physics

No Man's Sky
Shared: Exploration · Sandbox · Procedural Generation

PEAK
Shared: Exploration · Physics · Procedural Generation

The Long Dark
Shared: Exploration · Sandbox · First-Person

Gold Mining Simulator
Shared: Mining · Sandbox · Exploration

SnowRunner
Shared: Exploration · Sandbox · Simulation

Goat Simulator 3
Shared: Exploration · Sandbox · Physics

The Spotter: Dig or Die
Shared: Mining · Sandbox · Exploration

Keep Digging
Shared: Exploration · Mining · Sandbox

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

PANELKI
Shared: Snow · Sandbox · Procedural Generation

Totally Accurate Battle Simulator
Shared: Sandbox · Simulation · Physics

Internet Cafe Simulator 2
Shared: Exploration · Sandbox · First-Person

Out of Ore
Shared: Exploration · Sandbox · Simulation

Barn Finders
Shared: Exploration · Casual · Indie

Kerbal Space Program
Shared: Sandbox · Physics · Exploration

Mon Bazou
Shared: Sandbox · Exploration · First-Person

Terraria
Shared: Sandbox · Exploration · Adventure

鬼谷八荒 Tale of Immortal
Shared: Sandbox · Exploration · Simulation

Fallout 4
Shared: Exploration · Adventure · First-Person

Firewatch
Shared: Exploration · Adventure · First-Person

Content Warning
Shared: Exploration · Procedural Generation · Physics