Set in the grim future of the Warhammer 40,000 universe, "Chaos Rising" is a standalone expansion to "Dawn of War 2" that introduces some new units, new maps, and a new campaign mode. While some neat new stuff has been added, the bottom line is: if you didn't like the original game, nothing about Chaos Rising is going to change your mind.
The game's campaign picks up from where the original DOW2 campaign left off - if you have a completed save file, you can import it to keep your stats and gear from the previous campaign (though for reasons that basically add up to "gameplay contrivance", all your high-class Terminator armor is broken at the start). The level cap has been raised to 30 to provide for more advancement, and there's a bunch of new wargear to collect, including some new types of weapons not found in the original game.
The new gimmick in the campaign is corruption; in every mission, there will be a corrupt option (usually involving failing a side mission) and a pure option (usually involving going out of your way to do something). Embracing corruption gives you the option to use new, more powerful Chaos weapons, as well as providing various stat boosts. However, the plot will change depending on how chaotic individual units are - only having a completely pure team will get you the best ending. While I didn't like the squad members in the original DOW2, the fact that they had more weaknesses and vulnerabilities in Chaos Rising (due to the risk of corruption) made them at least a little more likable, and the fact that you could have some control over the story was neat.
The new Chaos faction for skirmish mode is kind of neat. Their starting stuff is similar to Space Marines, with tactical squads and heavy weapons, but as they get farther along they summon demons and monsters to complement their regular soldiers. One of their features is that for most squads you can choose between different "Dark Gods" to worship. Worshiping one god might give your squad close-combat weapons, while worshiping another might make them more powerful against vehicles. While in essence it's the same as buying wargear for any other side, it's at least thematic. The Chaos voices aren't as cool as the ones in Dawn of War 1, but that's to be expected - at the very least, the voice of the Chaos Sorcerer has returned from the original Dawn of War, so fans of that game will get a nostalgic feel from him. However, the Chaos Lord is voiced by Stephen Blum, which wouldn't be a big deal except for the fact that he already voices 3 other characters in the game and uses the same voice for each one.
On the whole, if you enjoyed Dawn of War 2, then Chaos Rising just adds more content to the game for you to use. If you didn't, then nothing about the game has changed enough to make it worthwhile. The new maps are nice, but there's not enough of them to be worth it by itself. It's a good expansion, in line with original Dawn of War's expansions, but it also doesn't add enough to change anyone's mind about the game.
We purchased this game with our own money via Steam.