Great game with depth and replayability unlike other WW2 RTS games. Create your own WW2 history for any nation you like.
Want to be Germany, friendly with Russia and take over half the world, and then create a coup in USA to get them to ally with you? Well it happened in my game.
You can be any country, even Luxembourg if you choose with 1 territory. Naturally you would want to be one of the more powerful nations, but the ability is there. There has been historical research and many real life events occur and effect your nation depending on what choice you take in the event. Every nation has unique tech teams based on historical companies, and countries have different doctrines which affect the usefulness and price of certain units. Specific leaders can be assigned to each division that were real commanders in the war. There is much depth in the game.
It is much like the old school war strategy board games with bonuses and such that you would need long winded calculations to figure out moves and success, but the game does it for you of course.
The game might have a longer than usual learning curve, especially if you did not play any of the previous games as I hadn't, but once you get past that it will seem very simple and common sense to you.
One technical issue with the game is that the resolution is stuck at 1024x768, but you can find a hack for it which increases the resolution. However the lack of native resolution changing is definitely a pain.
HoI 2 has depth and replayability that draws me to keep going back to play it, among many other WW2 strategy and RTS games I have.