Games like Umbral Coterie
Games like Umbral Coterie include RimWorld, Stronghold Crusader: Definitive Edition, Stronghold Crusader HD (2012), Stronghold: Definitive Edition, and Stronghold HD (2012). We matched them by the tags players give Umbral Coterie on Steam (Strategy, Colony Sim, Real Time Tactics, Isometric, and Pixel Graphics): closest matches first, and among equally close ones the better-known games.

RimWorld
Shared: Colony Sim · Strategy · Base Building

Stronghold Crusader: Definitive Edition
Shared: Strategy · Real Time Tactics · Colony Sim

Stronghold Crusader HD (2012)
Shared: Real Time Tactics · Colony Sim · Strategy

Stronghold: Definitive Edition
Shared: Strategy · Real Time Tactics · Colony Sim

Stronghold HD (2012)
Shared: Real Time Tactics · Colony Sim · Medieval

Mount & Blade II: Bannerlord
Shared: Strategy · Medieval · Open World

Going Medieval
Shared: Colony Sim · Strategy · Base Building

Oxygen Not Included
Shared: Colony Sim · Base Building · Strategy

They Are Billions
Shared: Colony Sim · Strategy · Base Building

Stronghold 2: Steam Edition
Shared: Real Time Tactics · Colony Sim · Medieval

Banished
Shared: Colony Sim · Strategy · Medieval

Dungeon Settlers
Shared: Colony Sim · Strategy · Base Building

Stronghold: Warlords
Shared: Colony Sim · Real Time Tactics · Medieval

Age of Empires II (Retired)
Shared: Strategy · Medieval · Base Building

Cult of the Lamb
Shared: Colony Sim · Base Building · Strategy

Songs of Syx
Shared: Colony Sim · Strategy · Base Building

Shadow Tactics: Blades of the Shogun
Shared: Strategy · Real Time Tactics · Isometric

Rise to Ruins
Shared: Colony Sim · Strategy · Pixel Graphics

Desperados III
Shared: Strategy · Real Time Tactics · Isometric

The King is Watching
Shared: Strategy · Dark Fantasy · Base Building

Manor Lords
Shared: Strategy · Base Building · Colony Sim

Total War: WARHAMMER III
Shared: Strategy · Real Time Tactics · Dark Fantasy

Becastled
Shared: Strategy · Colony Sim · Base Building

Space Haven
Shared: Colony Sim · Strategy · Base Building