The second expansion for Relic's hero-focused science fiction RTS broadens the scope to include more factions and units, but it comes at a price. Shaking up a formula that has been running unchanged through the large base game and first add-on isn’t a bad idea, but the original design's elegance was a big part of its draw. Adding a bunch of complications and caveats, while undeniably increasing the size of the toolbox at the player's disposal, doesn't make the gameplay any better.
I should be clear that this discussion of changing designs and unnecessary complexity is in regard to the single-player campaign. Multiplayer in Retribution is a marginal upgrade that retains the basic structure of its predecessors while thankfully ditching Games for Windows Live and adding new maps and heroes. I can't see anything that would alienate fans, and having another Last Stand map is great. If you're an established Dawn of War II online player, go ahead and skip the incoming complaints about Retribution's lackluster campaign and go buy the game already. Multiplayer-curious newbies beware: Jumping into competitive play at this point is going to match you up against players who have two years of experience with the game if not the few new units in Retribution. Be prepared to swim with the sharks.
The Retribution campaign's narrative suffers by being told from six different perspectives. Though you can play any of the six races, the overall story doesn't change (though your character's motives for pursuing it do). Dawn of War II, and particularly the Chaos Rising expansion, did an excellent job of staying tightly tied to a tiny cast of characters and using limited storytelling resources to flesh them out a little bit. Retribution's larger ensemble spreads the story too thin. There are some great moments, mostly around the Imperial Guard's Inquisitor and Ork pirate Cap'n Bludflagg, but the overall tale falls flat.
Previous Dawn of War II campaigns have put you exclusively in control of four heroes at a time. Retribution allows you to replace your auxiliary heroes (not your commander) with elite infantry squads, and to summon reinforcing infantry squads from on-map bases. This is great in theory – more options, huzzah! – but in practice having more units to control dilutes the awesomeness among your forces instead of concentrating it on your heroes. The result is a small-scale RTS that loses the unique flavor that Dawn of War II worked so hard to create. Using more units isn't a total disaster, but it is decidedly uninspiring compared to customizing heroes into well-honed killing machines.
The good news is that you can ignore most of this fluff and reinvest your resources back into your heroes, playing the campaign much like the older ones. Unfortunately, Retribution's level design is a step back. Dawn of War II maps have always been relatively linear, but these railroad you to an unprecedented degree. I felt like I was trying to figure out what the next step the level designer wanted me to take was, rather than coming up with a winning strategy based on my troop of elite heroes.
All that said, the new factions are interesting to play and feel reasonably well balanced. From the Chaos Marines' Warp energies and Nurgle's plagues to the Orks' ever-growing Waaagh!, the six sides present unique mechanics and solid, powerful tactical possibilities. Unless you're going to dive into multiplayer, though, Retribution is a mediocre expansion pack even though the base gameplay is still quite good. Pick up Chaos Rising instead, which you should have done anyway because it is fantastic.