Steam now offers the Dark Angels expansion for Space Hulk Ascension for Windows, OS X, and Linux, offering a 10% launch discount for the next week. Here's the deal:

Independent developer Full Control today announced that the third expansion for Space Hulk: Ascension is live for Windows PC, Mac and Linux on Steam. The Dark Angels Expansion “Bringer of Sorrow” unlocks the Deathwing of the Dark Angels Chapter and includes a further 20 story missions, and 20 flash missions for players to conquer.|

Featuring over 25 hours of content, Space Hulk: Ascension - Dark Angels continues to add incredible features and value to the turn-based strategy game. Written by Black Library author Graeme Lyon, the story campaign “Bringer of Sorrow” sees the planet Corinthe under attack by Tyranid forces, with a newly emerged Space Hulk that has to be eliminated by the Deathwing.

“I hope players are excited for the strategic options this expansion will afford them”, said Thomas Hentschel Lund, CEO of Full Control. “The Apothecary will give your team some incredible buffs, while the Plasma Cannon is one of the most destructive weapons the Genestealers will have the displeasure of facing!”

Plasma Cannons shoot out huge fireballs of glowing plasma that splash across large areas, causing insane amounts of damage. They can be overcharged for additional splash damage. The Apothecary is a support class that complements players command slot in their squad, and bolsters the resolve of nearby Terminators and supports defensive play styles.