I decided to give the USSR a try on veteran vanilla difficulty.
I focused on building a strong infantry army and rushed T-34s to give me a counter-punch if necessary. I intentionally slightly neglected my fighter production given the resources demanded to fully win an early air war would have otherwise crippled my land forces. After building an adequate industrial base, I elected to build a line of level 5 defense forts along my border with the Axis powers (current and future).
The game proceeded fairly historically until my Winter war where I crushed the Finns. The Germans shared Poland with me and immediately pivoted to France for an early submission. This concerned me, but Germany largely focused on others continental matters before declaring a fairly late war against me in July, '41.
My line of forts and anti-tank equipped infantry helped me hold my initial defensive positions until September '41, when I allowed my front-line forces to retreat beyond my secondary defensive line (2 provinces away with no forts) and form a new secondary defense line. This initial secondary line is still holding in late November '41. I’m hopeful it will hold until winter sets in and I’m able to allocate my production to push out another few dozen infantry divisions.
Overall, I’m happy with the progress so far. The Germans have been blunted and their 2M causalities will hurt them far worse than the 250k causalities I’ve suffered will hurt me. Another season of this and my superior manpower should allow me to begin driving west.