Games like T-Minus 30
Games like T-Minus 30 include Manor Lords, RimWorld, Against the Storm, Frostpunk, and Kingdoms and Castles. We matched them by the tags players give T-Minus 30 on Steam (City Builder, Strategy, Simulation, Base Building, and Colony Sim): closest matches first, and among equally close ones the better-known games.

Manor Lords
Shared: City Builder · Strategy · Simulation

RimWorld
Shared: Strategy · Base Building · Colony Sim

Against the Storm
Shared: Strategy · City Builder · Simulation

Frostpunk
Shared: City Builder · Strategy · Colony Sim

Kingdoms and Castles
Shared: City Builder · Colony Sim · Simulation

Prison Architect
Shared: Simulation · Base Building · Strategy

Workers & Resources: Soviet Republic
Shared: City Builder · Strategy · Simulation

Cities: Skylines
Shared: City Builder · Simulation · Strategy

Dwarf Fortress
Shared: Simulation · Base Building · Strategy

Empires of the Undergrowth
Shared: Strategy · Simulation · City Builder

Norland
Shared: Strategy · City Builder · Simulation

Banished
Shared: City Builder · Strategy · Simulation

Kingdoms Reborn
Shared: City Builder · Colony Sim · Base Building

Foundation
Shared: City Builder · Simulation · Strategy

Ostriv
Shared: City Builder · Strategy · Simulation

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

Captain of Industry
Shared: Simulation · Base Building · Strategy

Going Medieval
Shared: Strategy · Base Building · Colony Sim

Infection Free Zone
Shared: City Builder · Base Building · Strategy

Frostpunk 2
Shared: City Builder · Strategy · Simulation

Cities: Skylines II
Shared: City Builder · Simulation · Strategy

Endzone - A World Apart
Shared: City Builder · Strategy · Simulation

IXION
Shared: City Builder · Strategy · Colony Sim

Whiskerwood
Shared: Strategy · City Builder · Simulation