Games like Subject Zero
Games like Subject Zero include Democracy 4, Crusader Kings III, Victoria 3, 911 Operator, and Imperator: Rome. We matched them by the tags players give Subject Zero on Steam (Outbreak Sim, Strategy, Political Sim, Real Time Tactics, and Artificial Intelligence): closest matches first, and among equally close ones the better-known games.

Democracy 4
Shared: Strategy · Political Sim · Simulation

Crusader Kings III
Shared: Strategy · Simulation · Grand Strategy

Victoria 3
Shared: Strategy · Political Sim · Simulation

911 Operator
Shared: Strategy · Simulation · Management

Imperator: Rome
Shared: Strategy · Political Sim · Simulation

Plague Inc: Evolved
Shared: Strategy · Outbreak Sim · Simulation

Do Not Feed the Monkeys
Shared: Political Sim · Strategy · Management

Beholder
Shared: Political Sim · Strategy · Simulation

Crusader Kings II
Shared: Strategy · Political Sim · Grand Strategy

Dune: Spice Wars
Shared: Strategy · Management · RTS

Victoria II
Shared: Strategy · Political Sim · Grand Strategy

Dummynation
Shared: Strategy · Simulation · Grand Strategy

Game Dev Tycoon
Shared: Strategy · Simulation · Management

Beholder 2
Shared: Strategy · Political Sim · Simulation

Manor Lords
Shared: Strategy · Simulation · Management

Total War: WARHAMMER III
Shared: Strategy · Real Time Tactics · RTS

Democracy 3
Shared: Political Sim · Strategy · Simulation

SuperPower 3
Shared: Strategy · Political Sim · Simulation

Age of History II
Shared: Strategy · Political Sim · Grand Strategy

Tropico 6
Shared: Strategy · Political Sim · Simulation

Power & Revolution 2022 Edition
Shared: Strategy · Simulation · Political Sim

Total War: WARHAMMER
Shared: Strategy · Simulation · Real Time Tactics

SuperPower 2 Steam Edition
Shared: Strategy · Political Sim · Simulation

Beholder Conductor
Shared: Political Sim · Strategy · Simulation