Games like Rionag: Survey Fleet
Games like Rionag: Survey Fleet include Kerbal Space Program, Dyson Sphere Program, Kerbal Space Program 2, X4: Foundations, and shapez 2 - Factory. We matched them by the tags players give Rionag: Survey Fleet on Steam (Space Sim, Simulation, Exploration, Building, and Science): closest matches first, and among equally close ones the better-known games.

Kerbal Space Program
Shared: Simulation · Space Sim · Space

Dyson Sphere Program
Shared: Building · Space · Automation

Kerbal Space Program 2
Shared: Exploration · Space · Building

X4: Foundations
Shared: Simulation · Space Sim · Space

shapez 2 - Factory
Shared: Building · Simulation · Automation

Satisfactory
Shared: Automation · Base Building · Building

Spaceflight Simulator
Shared: Space Sim · Simulation · Exploration

Avorion
Shared: Space Sim · Exploration · Building

Empyrion - Galactic Survival
Shared: Simulation · Space · Building

Space Engineers
Shared: Building · Simulation · Space

Schedule I
Shared: Simulation · Management · Automation

Elite Dangerous
Shared: Space Sim · Exploration · Simulation

Oxygen Not Included
Shared: Building · Base Building · Simulation

Captain of Industry
Shared: Simulation · Automation · Building

Prison Architect
Shared: Simulation · Building · Base Building

Factorio
Shared: Automation · Base Building · Building

Space Haven
Shared: Simulation · Space · Base Building

EVE Online
Shared: Space Sim · Exploration · Simulation

Stationeers
Shared: Automation · Base Building · Building

Techtonica
Shared: Simulation · Building · Exploration

Automation - The Car Company Tycoon Game
Shared: Simulation · Building · Management

Cities: Skylines
Shared: Simulation · Building · Management

SpaceBourne 2
Shared: Space Sim · Base Building · Space

Mars Horizon
Shared: Space Sim · Space · Science