Hearts of Iron 2 not only builds on its predecessor's gameplay, but significantly refines and adds to the experience.
As someone who played the first Hearts of Iron to death, I appreciate the vast changes present in the second version. HOI2 is by and large a better game, the improvements in resource gathering , military command, User interface and depth of historical accuracy surpass the first version.
Resource gathering in this game is based around Power, Steel, Oil and Rare materials. The trade and prodauction of these is vital to a successful economy.
Military command in this game is much improved allowing players greater ability to effect the outcome they desire in a given battle through skill; chance, while present, can be minimised by an effective general.
The depth of Historical accuracy is actually mindblowing. Every countries' military is led by the real generals of the time, each with positive and negative attributes. Weapons, vehicles and technologies are all accurate as well.
The user interface, one of the big let downs of the previous game is also improved, allowing a more enjoyable and less frustrating gameplay experience.
I recommend this game to the strategy gamer who craves real historical depth, the casual historian may be turned away at first by the sheer depth on offer.