Here is the full list of all 24 Winter War 1939 achievements.
Kill 100 enemies playing as Finns
Kill 100 enemies playing as Soviets
Destroy 50 Soviet tanks
Destroy 50 Finnish tanks
Hit 25 enemy targets with Molotovs
Travel 10km on Skiis
Destroy 25 Soviet Airplanes
Destroy 25 Finnish Airplanes
Win all Finnish battles
Win all Soviet battles
Win Summa battle as Finns
Win Summa battle as Soviets
Win Galitsina battle as Finns
Win Galitsina battle as Soviets
Win Muolajarvi as Finns
Win Muolajarvi as Soviets
Win Perkjarvi as Finns
Win Perkjarvi as Soviets
Win Raate Road as Finns
Win Raate Road as Soviets
Win Tolvajarvi as Finns
Win Tolvajarvi as Soviets
Win Honkaniemi as Finns
Win Honkaniemi as Soviets