Ironclad Games' 4X strategy game Sins of a Solar Empire has finally made its way to Steam. Sins, formerly an exclusive for the digital store Impulse, can be purchased on Steam for $19.99.

"With the sale of our former PC digital download technology to GameStop earlier this year, we no longer have any conflicts of interest in offering our titles to other digital distribution channels," said Brad Wardell, CEO of Sins publisher Stardock. "We are starting with Sins of a Solar Empire: Trinity with other titles being made available over the coming weeks."

Steam is celebrating the game's debut on their store with a discount. For a limited time, you can pick up Sins for $14.99. The offer will end on November 23rd.

The version being offered is called Sins of a Solar Empire: Trinity. It includes the base game as well as the Entrenchment and Diplomacy mini-expansions released after launch. These expansions added new units/structures and revamped the political system of the game, respectively.

In Sins, players build an empire spanning the galaxy. They must gather resources, research new technologies, forge alliances, and direct their fleets in battle. You can face either A.I. or human opponents. It earned rave reviews upon release in 2008 and has sold over two million copies to date.

Ironclad is currently working on Sins of a Solar Empire: Rebellion, a larger, standalone expansion. It's expected to arrive this Spring.