Players control the actual units that fought in the campaign. Axis units mostly represent army corps. These include German, Finnish, Italian, Hungarian, Spanish and Romanian units. German tank units provide the real striking power for the Axis, and these are the strongest units in the game. The German infantry is also numerous and strong. The other Axis units are not usually as powerful as the German ones, though the Hungarian unit is good and there is a Romanian cavalry corps.

Soviet units are generally armies. Some of these are able to stand up to the Germans, but most cannot; while the Soviets start out with a very powerful army the first Axis turn is rough on the Red Army. The Soviet player must place his or her forces carefully and choose the time and place for counter-attacks. The Soviet player does have the aid of fleets in both the Baltic and the Black Seas, allowing landings behind enemy lines and sometimes support in combat. The Red Army of Workers and Peasants has many tank units, but they are not as strong as the German panzers. It can counter with paratroopers and shock troops, special units not available to the Axis.

The original game was published in 2004. The 2016, Avalanche Press released an updated "Player's Edition", more pieces, a larger map and more scenarios. There are 200 playing pieces in the Player's Edition (the first edition had 140) and a 28x22-inch map (the first edition’s was 22x17 inches) by Guy Riessen. There’s an introductory scenario for the 1939 German invasion of Poland, but the main event is the 1941 Axis attack on the Soviet Union. There are additional scenarios built around Operation Barbarossa plus variations like Turkish intervention.