Games like Seasteader
Games like Seasteader include Cities: Skylines, Kingdoms and Castles, Foundation, Banished, and Manor Lords. We matched them by the tags players give Seasteader on Steam (Strategy, Simulation, Indie, City Builder, and Economy): closest matches first, and among equally close ones the better-known games.

Cities: Skylines
Shared: Simulation · City Builder · Strategy

Kingdoms and Castles
Shared: City Builder · Simulation · Strategy

Foundation
Shared: Simulation · Strategy · City Builder

Banished
Shared: Strategy · City Builder · Simulation

Manor Lords
Shared: Strategy · Simulation · City Builder

Anno 1800
Shared: Strategy · Simulation · City Builder

Transport Fever 2
Shared: Strategy · Simulation · City Builder

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

Rise of Industry
Shared: Strategy · Simulation · Economy

Game Dev Tycoon
Shared: Simulation · Strategy · Indie

Against the Storm
Shared: Strategy · Simulation · City Builder

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

Frostpunk
Shared: Strategy · City Builder · Resource Management

Captain of Industry
Shared: Simulation · Strategy · Resource Management

Jurassic World Evolution
Shared: Simulation · Strategy · Management

Anno 2070™
Shared: Strategy · Simulation · City Builder

Farthest Frontier
Shared: Strategy · City Builder · Resource Management

Tropico 5
Shared: Strategy · Simulation · City Builder

Tavern Master
Shared: Simulation · Strategy · Management

Tropico 6
Shared: Strategy · Simulation · City Builder

Ostriv
Shared: Strategy · Simulation · City Builder

Prison Architect
Shared: Simulation · Strategy · City Builder

Jurassic World Evolution 2
Shared: Simulation · Strategy · Management

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