We described Unity of Command (opens in new tab) as "Wargame of the Year material" (opens in new tab) back in March, and as the year draws to a close that's looking more and more likely. The cute unit graphics might lead you to believe this is more of a casual strategy game, but underneath the charming exterior lies the barely beating heart of a wargame. And it's one that's just received a major expansion. The Red Turn DLC offers, among other things, a huge new campaign focusing on the Soviets - full details lie suppressed beneath the break.
Set near the end of the Stalingrad campaign, Red Turn includes a "gigantic Soviet campaign featuring 17 scenarios", as well as "two standalone Axis scenarios", four PVP scenarios, and 39 new units including "Panther and T-34/85 armor". I don't know what that last one is, but my WWII-ignorant brain is now imagining the T-51b Power Armor from Fallout 3 and New Vegas - I'm probably way off the mark.
The Red Turn DLC is available from the Unity of Command (opens in new tab) site or from Steam (opens in new tab) for $10/roughly £7.