I did something very cool while I was playing the World War II RTS Hearts of Iron.
I wanted to try and do what Stalin was planning to do in World War II, just sit back, and attack when everyone had exhausted themselves.
First off, when I took power I ordered all provinces to increase their industrial capacity, and did that a few times aftewards as well, and I built 24 infantry divisions to create a large strategic reserve.
After that, I focused on land and air force technologies, giving them up to 3/4 of my budget.
I did this up until 1944. In the meantime I annexed Finland after totally defeating them in the Winter War, and I signed the non-aggression pact with Germany. I didn't annex the Baltic States until 1942 though.
In 1943 the Germans were almost on the verge of victory in France with the help of their allies Slovakia, Italy, and Nationalist Spain.
I finished up all my technology research projects going on at the time and then built another 24 division. I now had several 12-division army groups. Most were of infantry with some tanks, and two were totally mechanized/motorized/armoured. I also built a very large modern air force.
I moved my armies close to Poland and then declared war on Germany. My troops did very well, advancing for about 2 months, coming right to the gates of Berlin. 10 divisions under Marshall Konev took Berlin for a while but were encircled. I decided to reinforce my attrited units and then let them sit for about a month as their organization came up. I also got about 24 infantry divisions completed in that time.
I then renewed the offensive, taking and holding Berlin, after which I sent about 12 division into Germany.
However, a large pocket of Germans still existed in southern Poland and Czechoslovakia, but I managed to defeat them later.
I also staged a coup in Denmark and made them join the Comintern.
I was able to annex Germany, and then I very easily took over Italy, making them a puppet, and then I advanced into northern Spain where my troops hooked up with American troops.
After that I upgraded divisions and air squadrons and built some ships for fun, but basically just consolidated my position and waited till 1948 when the Comintern won the game.