Based on the events of the Russian advances on Finland during and after the Winter War, up until the Vyborg Offensive in 1944, the Finland - Winter Storm add-on centers around the most iconic Finnish vs. Soviet military conflicts during World War II. Fight as the Finnish against an overwhelming threat, or play as the Soviets and crush the last Finnish defensive lines during the cold northern winter months.

• Finland - Winter Storm features two new mini-campaigns with six new singleplayer missions based on the events of the Russian advances on Finland during and after the Winter War, up until the Vyborg Offensive in 1944.
• Three new doctrine commanders to choose from: choose from the Finnish Army’s artillery expert Vilho Petter Nenonen, Finnish tank general Ruben Lagus and renowned general Karl Lennart Oesch as you consider your strategic options in tackling each mission.
• Sudden Strike 4: Finland - Winter Storm introduces 19 all-new vehicles.