In my 1939 Axis campaign, I've reached late August 1942. Invading the USSR has been pretty interesting. I've destroyed a lot of Soviet units, but because of the mechanics, I'm not sure it's working.
Basically, reinforcing a unit is half it's base purchase cost (e.g. buying a sub costs 200, but reinforcing it from 2 points to 10 costs 80). I'm not sure of the exact rule, but unless you've got a unit very well surrounded, destroying it allows your opponent to buy it back at half the regular purchase price (ie equivalent to reinforcement cost) and in half the time. The basic idea I think is that rear echelon and support elements of the unit escape to fight another day.
Sometimes I've been able to isolate some units before destroying them, especially at the start, but most of the time it's not feasible. The Soviet formations are too large, units don't move fast enough and there are too many zones of control to cut through. Most of the units I've wiped out I'm sure have been bought back at half price.
Which makes me think I could be in trouble. The log says the Soviets have lost 125 units so far. But they get over 1000 production per turn now. Replacing a basic infantry corps is only 75 production. If destroying a Soviet corps causes me to knock three of my corps from 10 to 8, then it's going to cost me 45 production and another turn off the invasion schedule to make that right.I think I'm spending over 500 a turn just replacing losses.
On the map, I'm on the border of Moscow, approaching from the south. I think I may be able to swing around the fortifications and take the city before winter hits. I messed up my approach to Leningrad in '41, so I'm still a long way from there. In the South, I am pushing to toward Stalingrad, but there are still so many damn units in the way.
I think a lack of strategic focus is catching up with me, and I might lose in the east. Which is pretty amazing considering that this is the basic difficulty level, with no AI advantage. Sure, the AI is good, but basic design choices in the game combine to make the decision in the east a dramatic struggle. There's just not enough time to keep your units in good condition and get to your targets.
Fighting the western Allies, I think I am doing better so far. My sub force is highly advanced, experienced and in good condition, and I've wiped out a number of light cruisers and destroyers. It's still painful fighting the destroyers, but I can take them down. Maybe I should send more surface raiders out there?
The Italian navy has been able to destroy the British med fleet bit by bit, and they are now down to one carrier trapped in port on Crete. Strong Italian and German forces have overrun Egypt and Palestine, and are on their way to "liberating" Iraq and then Persia. Perhaps due to losses in Africa, the British bombing campaign in Europe hasn't achieved anything so far.