Games like Hell Architect
Games like Hell Architect include Prison Architect, Kingdoms and Castles, Oxygen Not Included, Manor Lords, and RimWorld. We matched them by the tags players give Hell Architect on Steam (City Builder, Colony Sim, Base Building, Sandbox, and Management): closest matches first, and among equally close ones the better-known games.

Prison Architect
Shared: Base Building · Sandbox · Colony Sim

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

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

Manor Lords
Shared: City Builder · Base Building · Management

RimWorld
Shared: Colony Sim · Base Building · Sandbox

Dwarf Fortress
Shared: Colony Sim · Base Building · City Builder

Against the Storm
Shared: City Builder · Base Building · Colony Sim

Cities: Skylines
Shared: City Builder · Management · Sandbox

Timberborn
Shared: City Builder · Colony Sim · Sandbox

Empires of the Undergrowth
Shared: City Builder · Base Building · Colony Sim

Workers & Resources: Soviet Republic
Shared: City Builder · Base Building · Strategy

Foundation
Shared: City Builder · Sandbox · Management

Frostpunk
Shared: City Builder · Colony Sim · Base Building

Banished
Shared: City Builder · Colony Sim · Sandbox

The Universim
Shared: City Builder · Colony Sim · Sandbox

Norland
Shared: City Builder · Base Building · Colony Sim

Settlement Survival
Shared: City Builder · Colony Sim · Building

Cities: Skylines II
Shared: City Builder · Sandbox · Management

Ostriv
Shared: City Builder · Colony Sim · Management

Academia : School Simulator
Shared: City Builder · Colony Sim · Management

Going Medieval
Shared: Colony Sim · Base Building · City Builder

SimCity™ 4 Deluxe Edition
Shared: City Builder · Base Building · Sandbox

Space Haven
Shared: Colony Sim · Base Building · Management

Factorio
Shared: Base Building · Sandbox · Management