Games like Once Upon a Time in the Colony
Games like Once Upon a Time in the Colony include RimWorld, Oxygen Not Included, Kenshi, The Isle, and Stardew Valley. We matched them by the tags players give Once Upon a Time in the Colony on Steam (Simulation, Colony Sim, Farming Sim, Survival, and Western): closest matches first, and among equally close ones the better-known games.

RimWorld
Shared: Colony Sim · Survival · Simulation

Oxygen Not Included
Shared: Colony Sim · Survival · Simulation

Kenshi
Shared: Survival · Open World · Sandbox

The Isle
Shared: Survival · Simulation · Open World

Stardew Valley
Shared: Farming Sim · Simulation · Sandbox

Space Engineers
Shared: Simulation · Survival · Sandbox

Banished
Shared: Colony Sim · Simulation · Survival

Amazing Cultivation Simulator
Shared: Simulation · Sandbox · Colony Sim

Dwarf Fortress
Shared: Colony Sim · Simulation · Sandbox

Project Zomboid
Shared: Survival · Open World · Sandbox

Feed and Grow: Fish
Shared: Simulation · Survival · Open World

Dawn of Man
Shared: Colony Sim · Simulation · Survival

My Time at Portia
Shared: Farming Sim · Simulation · Open World

SPORE™
Shared: Colony Sim · Simulation · Open World

Flotsam
Shared: Colony Sim · Survival · Sandbox

7 Days to Die
Shared: Survival · Open World · Simulation

Stonehearth
Shared: Colony Sim · Simulation · Survival

Space Haven
Shared: Colony Sim · Survival · Simulation

Craft The World
Shared: Colony Sim · Survival · Sandbox

Don't Starve Together
Shared: Survival · Open World · Sandbox

Kingdoms and Castles
Shared: Colony Sim · Simulation · Sandbox

Rust
Shared: Survival · Open World · Sandbox

Stranded: Alien Dawn
Shared: Simulation · Survival · Colony Sim

Once Human
Shared: Open World · Survival · Simulation