"Warhammer 40,000: Dawn of War II is a real-time strategy/tactical role-playing video game developed by Relic Entertainment and published by THQ for Microsoft Windows based on the fictional Warhammer 40,000 universe. It is the sequel to the Warhammer 40,000: Dawn of War video game series.
Playable armies at the initial release of the game include the Space Marines, Orks, Eldar, and Tyranids.
The gameplay of Dawn of War II is markedly different from that of Dawn of War and its expansions. Jonny Ebbert, the game's lead designer, describes the feel of the game by saying that it "takes everything that was great about the original and combines it with the best that Company of Heroes had to offer." There is a heavier focus on cover, which gives more substantial defensive bonuses. Accordingly, there is also new emphasis on methods of dealing with units in cover. Some weapons, such as grenades and other explosives, can destroy cover, while others, such as flamers, ignore cover bonuses completely. Other differences between Dawn of War II and its predecessors include improved unit AI (squads under fire seek cover, for example), more realistically sized vehicles, and an improved physics engine.
As a Games for Windows - Live game, the game uses the Achievements system from Xbox LIVE, and is the first widely released, PC-exclusive game to use it. Because of this, a player must be able to connect to the Windows Live servers in order to access the game's multiplayer features. The game also requires authentication via Steam."
Source: Wikipedia, "Warhammer_40,000:_Dawn_of_War_II," available under the CC-BY-SA License.