Games like Flooded
Games like Flooded include Kingdoms and Castles, Cities: Skylines, Farthest Frontier, Frostpunk, and Manor Lords. We matched them by the tags players give Flooded on Steam (RTS, City Builder, Time Management, Resource Management, and Management): closest matches first, and among equally close ones the better-known games.

Kingdoms and Castles
Shared: City Builder · Resource Management · Management

Cities: Skylines
Shared: City Builder · Management · Building

Farthest Frontier
Shared: City Builder · Building · Resource Management

Frostpunk
Shared: City Builder · Resource Management · Building

Manor Lords
Shared: City Builder · Management · Building

Prison Architect
Shared: Building · City Builder · Management

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

Stronghold: Definitive Edition
Shared: City Builder · RTS · Building

Anno 1800
Shared: City Builder · RTS · Resource Management

Against the Storm
Shared: City Builder · Building · Management

Stronghold Crusader HD (2012)
Shared: City Builder · Building · Real Time Tactics

Foundation
Shared: City Builder · Management · Resource Management

Workers & Resources: Soviet Republic
Shared: City Builder · Building · Management

Anno 2070™
Shared: City Builder · RTS · Resource Management

SimCity™ 4 Deluxe Edition
Shared: City Builder · Building · Management

Anno 117: Pax Romana
Shared: City Builder · RTS · Building

Stronghold HD (2012)
Shared: City Builder · Building · RTS

Norland
Shared: City Builder · Management · Resource Management

Jurassic World Evolution
Shared: Building · Management · City Builder

Oxygen Not Included
Shared: Resource Management · Building · Management

Empires of the Undergrowth
Shared: City Builder · Building · Management

Pharaoh™: A New Era
Shared: City Builder · Management · Building

Jurassic World Evolution 2
Shared: Management · Building · City Builder

Stronghold Crusader: Definitive Edition
Shared: City Builder · Building · RTS