On the plus side, I really like the world map, research system, national foci, battle planner and ability to play pretty much any country. Construction is also interesting in many ways, but it’s also a bit strange in that you can’t stockpile resources, nor does it consume fuel when you let loose your machines of war. In fact the entire logistics model is a bit odd. It get that the game designers (Paradox Studios) were trying to keep things simple since, let’s face it, micro-managing supply lines isn’t much fun. The problem is it can be weirdly easy to deploy military units all over the planet, even in places that would demand a herculean effort to keep supplied. Oddly enough Axis and Allies addresses this issue by movement limitations. Speaking purely in terms of troopship speeds, Imperial Japan probably could have landed a couple divisions of men on the west coast of Africa in a matter of months, but in the board game it takes a year or more of in-game time to do so. This might sound ridiculous at first, but when you look at it as an abstraction of the time needed to plan, prepare and set up the necessary infrastructure to keep tens of thousands of fighting men fed and properly outfitted on the opposite side of the globe then a year starts to sound pretty optimistic. In fact Japan didn’t have the merchant marine fleet or fuel oil resources need to maintain an occupational force on the Hawaiian Islands, let alone the interior of Australia. I’m pretty sure they lacked the necessary manpower to dominate the vast regions and populations of mainland China or India too, but you can conquer all those places and more in Hearts of Iron 4.
The last big problem with Hearts of Iron 4, as I see it, is the AI with regards to the division designer. This problem might be fixed by the time I get around to posting this, as it stands right now most computer controlled divisions consist of little more than a small number of infantry battalions with little in the way of support companies or mechanized units.