21 Real-Time · Sci-fi games your group can play together online, including Sins of a Solar Empire II, Executive Assault 2, and Per Aspera.
All games: 21
Battle for galactic dominance in this real-time 4X strategy game with unrivaled scale! You’ll explore, expand, exploit, and exterminate through military force, diplomacy, trade, culture, influence, and other underhanded tactics.
The RTS/FPS phenomenon has moved into space! Build your base on an asteroid, command fleets of starships for epic battles, pilot fighters, mine and trade resources, assemble robots to defend or assault other stations. Take sole command or share the glory as you fight for control of the quadrant.
Make Mars your own! Take control of the world’s most sophisticated AI (AMI) and terraform the surface of the Red Planet for a city-building experience on a planetary scale. Transform this barren world into a lush paradise and explore the surface for any ancient secrets that may be waiting.
A classic real-time strategy game with an epic single player campaign, multiplayer & coop, set in the alternate reality of 1920+
Updated in 2026 for modern systems, Krush Kill 'N Destroy 2: Krossfire is a fast and furious post-apocalyptic real-time strategy game where you have to be quick or be dead. Play as one of three unique factions in the struggle to seek out and conquer oil fields to fuel your army.
The most devious and acclaimed artificial intelligence in strategy gaming is better than ever. A grand strategy/RTS hybrid that reverses many conventions of both genres. Take territory without attracting attention, build your empire with care, and adapt to an ever-evolving galactic battleground.
With 100+ truly unique units, Zero-K is an RTS of freedom and creativity, tempered by a decade of refinement. Sculpt land into a castle and throw invaders off it with a Jugglenaut. Explore a massive campaign, solo or co-op. Hop online for epic 32 player battles or fast paced 1v1, on 100s of maps.
Battlezone: Combat Commander remasters FPS-RTS classic Battlezone II with slick new visuals, brand new achievements, Steam Workshop support and much more! The solar system is at war. Take command.
Lead the great armies of the Star Wars™ Episode II: Attack of the Clones saga in intense real-time strategy clashes. Enter the fray as the Galactic Empire, Rebel Alliance, Wookies, Trade Federation, Gungans or Royal Naboo to determine the course of the Galactic Civil War.
Satellite Reign is a real-time, class-based strategy game, set in an open-world cyberpunk city. You command a group of 4 agents through rain-soaked, neon-lit streets, where the law is the will of mega-corporations.
Creeper World 3 is what happens when cellular automata takes over a strategy simulation. Instead of discrete units that attack your base, a fluid-like substance spreads over the terraformable terrain. Your base, your weapons, your strategy... you must adapt them all.
Join an online or LAN team match in Original War, where named specialists, base building, and map-specific rules turn a retro RTS into a hands-on group effort.
2280 A.D. The last few survivors of a ruined Earth seek a new home: Mars, a planet whose inhabitants didn't take too kindly to outsiders. The Red Solstice is a tense, tactical, squad-based action game. Fight to survive with up to 8 players in co-op, or lead your own squad in single-player mode.
Explore war-torn post-apocalyptic landscapes and take fight against enemies using various weapons in this FPS/RTS hybrid.
Executive Assault is an indie real-time strategy/first-person shooter where you can not only build your base and create armies, but also take control of your units and fight as one of them.
BattleGroupVR is a first person real-time space strategy where you lead a fleet of powerful warships into battle from the bridge of your own flagship. Assemble your fleet, upgrade your load-outs, train your captains, engage the enemy and secure the sector. Try not to go down with the ship.
Build a galactic transportation empire and supply humanity with everything it needs to colonize the stars. In this sci-fi logistics simulator, grow your company from a local transport agency into an interstellar logistics behemoth! Singleplayer, vs AI, and online multiplayer.
Drox Operative 2 is a starship action RPG with warring alien races, fierce space battles, a dynamic, evolving galaxy, and co-op multiplayer for Windows and Linux.
Colony Siege combines the best of RTS and tower defense, including base building, mazing, and unit physics. Defend Earth's remaining colonies using an arsenal of deadly weapons to torch, slice, throw, and impale swarms of alien invaders.
Moduwar is an adaptive organic RTS where you control an alien creature, Modu - and your body is your army. Grow new organs, split, merge and mutate them into unique units that adapt to your needs as you fight against human and alien threats in single and multiplayer modes.
Inspired by the classic arcade Lunar Lander game, in Galactic Lander you control a delicate scientific spaceship which you must deliver from point A to point B, either alone, or with a friend in a co-op level, potentially made by the game's own Steam Workshop community!