Hearts of Iron is a strategy game on a global scale. Set during the beginning of World War II and spanning up to 12 years, you get to take the reigns of a single country in the conflict. But where other games only let you pick the major contenders, here you can see what would happen if Switzerland would have picked a side, or if Yugoslavia had remained independent.
The game takes place in real-time, with the smallest increment being in hours. The gameplay can be sped up or slowed down, but so much is going on that you'll initially want to take it easy. Unfortunately, in the long run, the total time of a single game is relatively short. No matter what is going on, the game will end at 1948 at the very latest. Expanding the overall time to see drastic changes in history would have been nice, but instead you are usually cut off in the middle of a bloody struggle. There are also only three scenarios to choose from, severely limiting the replay value.
As with most strategy games, there is a tech tree. Hearts of Iron's tech tree is quite possibly one of the most convoluted and unpleasant things I have ever seen. It is so detailed that 90 percent of what you research will never be used, and you can easily get lost trying to navigate to the really important advances. This hindrance stops the flow of gameplay in its tracks.
As if that weren't enough, managing diplomacy and internal dissent is cryptic at best, and you'll spend most of the game paused trying to figure out what to do. Managing your countries' supplies, along with your troops in the field, is virtually impossible by sea, all but forcing you to choose landlocked countries. You must set up convoys constantly, and there is absolutely no warning as to when one of your units is about to run out of supplies and totally disappear from the map.