Grey Goo gets fourth faction in free expansion

A fourth faction has invaded Petroglyph's sci-fi RTS, Grey Goo. The expansion, which is free to existing players, is called Descent of the Shroud, and introduces a fourth playable faction.

The Shroud are described as "destructive, alien life forms" who have "landed on Ecosystem Nine to feed off of its energy—and destroy the Human, Beta and Goo factions that stand in their way."

The expansion lands alongside a new Definitive Edition of the game, which comes with the following features:

A brand-new multiplayer faction: face off against—or play as—the Shroud
New units: the Humans' Valiant, the Beta's Squall and the Goo's Siphon
All DLC, including the "Emergence" and "Descent of the Shroud" campaigns
Mission 16: "Herald of Silence"
The complete game soundtrack
Additional Shroud-related accomplishments
An extensive gameplay balance overhaul