Garry's Mod

Sandbox physics mod for Half-Life 2 that became so popular that it was made into a standalone release

Euro Truck Simulator 2

Role playing game where you travel across Europe as a truck driver exploring various cities

Arma 3

Combat warplay in a military setting with a variety of single player and multiplayer options

The Forest

Scavenge resources, craft weapons and make defenses to survive against mutants who want your life

Mount & Blade II: Bannerlord

The horns sound, the ravens gather

Don't Starve Together

A multiplayer feature that expands on the fantasy survival game, Don't Starve

Space Engineers

Create a new world in space and see if you can protect it from aliens

Stardew Valley

Farm to your heart's content in this fun simulation game with animals to feed too

Don't Starve

Try to survive in a world of magic and science with minimal resources

7 Days to Die

Survive, explore, scavenge and rebuild in a zombie-infested world with life and death strategic decisions