Games like Rome in a Day
Games like Rome in a Day include Age of Empires II (Retired), Age of Empires III: Definitive Edition, Tower Dominion, Mindustry, and Cossacks 3. We matched them by the tags players give Rome in a Day on Steam (Strategy, Stylized, Resource Management, Old School, and Isometric): closest matches first, and among equally close ones the better-known games.

Age of Empires II (Retired)
Shared: Strategy · Resource Management · RTS

Age of Empires III: Definitive Edition
Shared: Strategy · Base Building · RTS

Tower Dominion
Shared: Strategy · Base Building · Tower Defense

Mindustry
Shared: Resource Management · Strategy · Base Building

Cossacks 3
Shared: Strategy · Resource Management · RTS

They Are Billions
Shared: Strategy · Base Building · RTS

Age of Mythology: Retold
Shared: Strategy · Base Building · Resource Management

Manor Lords
Shared: Strategy · Base Building · Resource Management

Factorio
Shared: Resource Management · Strategy · Base Building

The King is Watching
Shared: Strategy · Base Building · Resource Management

Diplomacy is Not an Option
Shared: Resource Management · Base Building · Strategy

Tempest Rising
Shared: Strategy · Base Building · Isometric

Stronghold: Definitive Edition
Shared: Strategy · RTS · Real Time Tactics

Age of Darkness: Final Stand
Shared: Strategy · Base Building · Stylized

Total War: ROME II - Emperor Edition
Shared: Strategy · Rome · RTS

Stronghold Crusader HD (2012)
Shared: Strategy · Base Building · Real Time Tactics

Pioneers of Pagonia
Shared: Strategy · Resource Management · Base Building

Farthest Frontier
Shared: Strategy · Resource Management · Base Building

Thronefall
Shared: Strategy · Tower Defense · Base Building

Starship Troopers: Terran Command
Shared: Strategy · Resource Management · RTS

Eyes of War
Shared: Strategy · Stylized · Isometric

Frostpunk
Shared: Strategy · Resource Management · Base Building

Broken Arrow
Shared: Strategy · RTS · Wargame

Against the Storm
Shared: Strategy · Base Building · Resource Management