https://store.steampowered.com/sub/90948/

FIGHT THE CHAOS. OR HARNESS ITS POWER.
Out of the ashes of war, a tentative truce emerges between the Humans, Beta and the Goo—but peace doesn’t last long. Ecosystem Nine finds itself thrust into turmoil once again with the arrival of a destructive, alien life form known as the Shroud.

Grey Goo is a real-time strategy (RTS) game that combines classic strategy mechanics and a balanced combat system with an emphasis on large-scale decision-making. It puts you at the center of a tactical struggle for survival—and ultimately, control of Ecosystem 9.

Take on the single-player campaign to command three factions: the Humans, masters of defensive architecture; the Beta, a proud, versatile alien race; and the Goo, an enigmatic, highly mobile life form. Or compete with any of the four multiplayer factions—including the disruptive, unpredictable Shroud.
Features
Fight—or play as—the Shroud, a brand-new, multiplayer faction.
Command new units: the Humans’ Valiant, the Beta’s Squall and the Goo’s Siphon.
Explore an additional story arc with “Grey Goo: Emergence,” and discover the Goo’s true intentions.
Take on the Shroud in Mission 16, “Herald of Silence."
Sharpen your battlefield tactics in the single-player campaign, or join the fray on Steam.
Join the fray on Steam and find opponents through skill-based matchmaking.
Change the rules of the battlefield with unit-altering tech upgrades.
Deliver devastating blows by constructing game-ending Epic units.
Take the battle offline via Local Area Network play.
Enhance your competitive edge with Replay Mode and Observer Mode.
Use the Map Editor to create your own battlefields and share them with the community via Steam Workshop.