Spell Cast
CO-OP Time survival game with roguelite elements, up to 10 players online
64% of 53 Steam reviews are positive$0.49
Co-op games like Sigma Protocol
If Sigma Protocol left you wanting something competitive and replayable, you have options. These co-op games line up well for what comes next. You can bring friends along for most of these.
Fair and Square
Try this small real time strategy and roguelike game where you need to defend your base against multiple waves . Each run you will have to choose between unique units and unique buffs.
Replayable, Tense, Fast-paced
100% of 8 Steam reviews are positive$7.99Colony Siege
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.
Replayable, Tense, Fast-paced
91% of 199 Steam reviews are positive$19.99Ashes of the Singularity: Escalation
A massive-scale real-time strategy game where you and co-op friends command thousands of units across huge maps. Pick the Post-Human Coalition or the Substrate, grab resource points, build bases and armies, and settle it together in multiplayer or against the AI.
Competitive, Replayable
76% of 2,715 Steam reviews are positivePlayers online now: 288$5.99Rusted Warfare - RTS
A throwback RTS built for huge land, air, and sea battles with friends. Team up against the AI, share control of your armies, and throw 50-plus units plus late-game experimentals at the problem until the map is yours.
Competitive, Replayable
96% of 6,756 Steam reviews are positivePlayers online now: 124$4.99Instant War
Embark on a military strategy 4X RTS game, in a world where your battle tactics and your massive army are the keys to victory. Instant War delivers an amazing battlefield experience in a realistic military game. As a commander, you develop your military base and lead your army to victory!
Competitive, Replayable, Tense
67% of 93 Steam reviews are positivePlayers online now: 9FreeD.O.T. Defence
Welcome to the frontlines! Build towers, muster armies, and conquer the map. Challenge yourself in the single-player campaign following the Chroma Wars, survive relentless waves in solo defense, or battle it out in local matches against friends and AI bots. Victory comes with the last HQ standing!
Competitive, Replayable, Fast-paced
85% of 212 Steam reviews are positive$9.74Frontline Crisis
Defend humanity's last hope, pilot a powerful mech, in Frontlines Crisis! A battlefield swarming with insects makes strategic and combat decisions crucial. Each decision will determine your fate. Defend humanity's last sanctuary, fight fiercely, and uphold human honor with wits and courage!
Replayable, Tense, Fast-paced
87% of 349 Steam reviews are positive$5.99Siegecraft Commander
Create the ultimate fortress and wreak havoc, raining destruction on your enemies with catapult-flinging fun!
Competitive, Replayable
58% of 36 Steam reviews are positive$19.99Settle and Battle: New Empires
A homage to classic real-time strategy games. Gather resources, build an empire, and command powerful armies to conquer the world. Lead six unique tribes, expand your territory, and engage in epic battles with hundreds of units on screen. Dominate in 18 missions and procedurally generated maps!
Competitive, Replayable
100% of 10 Steam reviews are positive$6.99Stellarcraft
Stellarcraft is a sci-fi tower defense adventure: explore alien planets, gather resources, build defenses, and fend off waves of enemies, solo or in 4-player co-op. 🚀
Replayable, Tense, Fast-paced
88% of 76 Steam reviews are positivePlayers online now: 1$9.99Zero-K
Zero-K is a free sci-fi RTS with giant robots, physics-driven battles, and a 70-mission campaign you can play solo or with co-op friends. Team up against the AI or waves of chicken-monsters, reshape the land together, and command huge armies without paying for an advantage.
Competitive, Replayable, Fast-paced
93% of 4,448 Steam reviews are positivePlayers online now: 156Free17.waves TD
17.waves is an online co-op tower defense game for up to four players. Strategize with your teammates to build, upgrade, and maintain your towers to defend your base from hordes of invading aliens.
Replayable, Tense, Fast-paced
94% of 17 Steam reviews are positive$5.19
Cheaper than Sigma Protocol
Mining Mechs
Pilot a mining mech, chew downward through dirt and rock, sell what you find, and buy better drills and cargo space.
89% of 2,623 Steam reviews are positivePlayers online now: 39$2.99
Miner Warfare
8 players local multiplayer bonanza with only 4 controllers!In Miner Warfare you dig for gold.
83% of 150 Steam reviews are positive$0.92
Destropolis
Destropolis is a top-down shooter game with a fully destructible environment, hundreds of enemies and nuclear explosions.
89% of 260 Steam reviews are positive$0.77
BULLET PARTY
The party co-op shoot ’em up! Become the king of the night club! Go alone or group your friends! Shoot the party crashers down!
95% of 73 Steam reviews are positive$0.49
Zombie Wasteland Together
Zombie Wasteland Together is a 1–4 player co-op zombie shooter set in a post-apocalyptic desert.
65% of 23 Steam reviews are positive$0.49
Dead Station Together
A deadly outbreak has consumed a remote space station. Team up with friends, recover DNA samples, rescue the crew, and survive against the infected…
79% of 33 Steam reviews are positive$0.49
Robot Roller-Derby Disco Dodgeball
Robots on skates throwing dodgeballs in a laser-lit club. You race around, catch incoming throws to knock out the thrower, and pull 360 stunt shots…
91% of 2,276 Steam reviews are positivePlayers online now: 15$0.98
Gamma Space
You play the role of a spaceship surrounded by an asteroid field.
50% of 2 Steam reviews are positive$0.79
The Superfluous
"The Superfluous" [soo-pur-floo-uh s] A cave-diving, sci-fi, rogue-lite, platformer with jet packs and lots of explosions.
74% of 35 Steam reviews are positive$0.79
Logistics Simulator
Logistics Simulator As an active member of a shipping company in a major city around the world, you can play with up to 10 friends in a multiplayer…
30% of 63 Steam reviews are positive$0.49
Bug Killers
Bug Killers – is a dynamic Top Down shooter where you will need to turn crowds of bugs-mutants into meat.
27% of 15 Steam reviews are positive$0.79
Hidden gems like Sigma Protocol
The Scouring
The Scouring is a fast-paced fantasy RTS where you and co-op friends build bases, raise human or orc armies, and hold out against nightly undead…
87% of 1,180 Steam reviews are positivePlayers online now: 13$17.49
D.O.T. Defence
Welcome to the frontlines! Build towers, muster armies, and conquer the map.
85% of 212 Steam reviews are positive$9.74
ZeroSpace
Team up in the Orion sector in this sci-fi RTS where you command infantry, mechs, artillery, and orbital strikes.
78% of 1,357 Steam reviews are positivePlayers online now: 77$39.99
Frontline Crisis
Defend humanity's last hope, pilot a powerful mech, in Frontlines Crisis!
87% of 349 Steam reviews are positive$5.99
War of Dots
War of Dots is a minimalist real-time strategy game stripped down to light units, heavy units, and cities.
81% of 7,796 Steam reviews are positivePlayers online now: 88Free
Warlords Under Siege
Warlords Under Siege is a mix of RTS and Roguelike genre, where you build a small city and defend it against continuous waves of enemies.
76% of 441 Steam reviews are positive$9.99
Silica
Silica lets one co-op friend command an RTS army from above while the rest fight inside it on foot, as humans or aliens across the dunes of Baltarus.
76% of 4,651 Steam reviews are positivePlayers online now: 171$24.99
Retro Commander
Retro Commander is a post-apocalyptic real-time strategy wargame (RTS).
77% of 379 Steam reviews are positivePlayers online now: 3Free
Colony Siege
Colony Siege combines the best of RTS and tower defense, including base building, mazing, and unit physics.
91% of 199 Steam reviews are positive$19.99
Circle Empires Rivals
A fast-paced RTS where you and your co-op friends each run a tiny kingdom on a map made of circles.
89% of 1,567 Steam reviews are positivePlayers online now: 10$15.99
Stellar Warfare
Space RTS with base building and ship customization. Personal passion project.
80% of 321 Steam reviews are positivePlayers online now: 1$19.99
Zero-K
Zero-K is a free sci-fi RTS with giant robots, physics-driven battles, and a 70-mission campaign you can play solo or with co-op friends.
93% of 4,448 Steam reviews are positivePlayers online now: 156Free
Newest co-op games like Sigma Protocol
Silica
Silica lets one co-op friend command an RTS army from above while the rest fight inside it on foot, as humans or aliens across the dunes of Baltarus.
76% of 4,651 Steam reviews are positivePlayers online now: 171$24.99
ZeroSpace
Team up in the Orion sector in this sci-fi RTS where you command infantry, mechs, artillery, and orbital strikes.
78% of 1,357 Steam reviews are positivePlayers online now: 77$39.99
D.O.T. Defence
Welcome to the frontlines! Build towers, muster armies, and conquer the map.
85% of 212 Steam reviews are positive$9.74
17.waves TD
17.waves is an online co-op tower defense game for up to four players.
94% of 17 Steam reviews are positive$5.19
Stellarcraft
Stellarcraft is a sci-fi tower defense adventure: explore alien planets, gather resources, build defenses, and fend off waves of enemies, solo or in…
88% of 76 Steam reviews are positivePlayers online now: 1$9.99
War of Dots
War of Dots is a minimalist real-time strategy game stripped down to light units, heavy units, and cities.
81% of 7,796 Steam reviews are positivePlayers online now: 88Free
Chip ‘n Clawz vs. The Brainioids
Build bases, lead an army of robots, and squash brains in this radical hybrid between RTS and third-person shooter.
84% of 90 Steam reviews are positivePlayers online now: 2$29.99
The Scouring
The Scouring is a fast-paced fantasy RTS where you and co-op friends build bases, raise human or orc armies, and hold out against nightly undead…
87% of 1,180 Steam reviews are positivePlayers online now: 13$17.49
Xeno Rangers
In this Coop Platformer Defense game, you must defend your HQ from enemy hordes by building your base and defenses wisely, while you fight using…
100% of 4 Steam reviews are positive$11.99
Fortress Frenzy
Start your world conquest with any faction you choose. Build and upgrade your production buildings. Plan and decide the composition of your army.
100% of 2 Steam reviews are positive$9.99
Warlords Under Siege
Warlords Under Siege is a mix of RTS and Roguelike genre, where you build a small city and defend it against continuous waves of enemies.
76% of 441 Steam reviews are positive$9.99
Settle and Battle: New Empires
A homage to classic real-time strategy games. Gather resources, build an empire, and command powerful armies to conquer the world.
100% of 10 Steam reviews are positive$6.99