Summary
For WW2 buffs who wonder "What If...?"
The Good
Paradox has had a string of engrossing geopolitical sims to date, from the Europa Universalis series to Victoria and Crusader Kings... Hearts of Iron 2 continue this fantastic legacy by not only outdoing its successor (Hearts of Iron), but arguably topping the legendary Europa Universalis 2 itself.
The interface and gameplay mechanics have been simplified from the original Hearts of Iron, which removes a lot of the duldrums and non-fun chores associated with the original. For example, in the original Hearts of Iron, upgrading units on the field after a new technology is developed required manually upgrading each and every unit... and if you controlled a large nation such as Germany or the Soviet Union, the process is simply torturous. In HOI2, however, upgrades are as simple as adjusting a slider in order to allocate resources to the upgrade process.
If left to play itself (if the player decides to play, say Bolivia and just watch the rest of the world duke it out) WW2 will unfold much like it did according to the history books. Germany will annex Austria and the Sudatenland, militarize the Rhineland, crush Poland and fight their war on two fronts. However, if the player becomes the "bully" on the block (say, as an aggressive Soviet Union or France) the war will be entirely different. Germany might decide to "play nice" and a whole new string of events will unfold.
A lot of WW2 "What ifs" are explored. From the realistic "What if Italy or Japan didn't join the Axis" or "What if the Spanish Nationalists lost the war against Republican Spain?" to the absurd "What if the Soviet Union annexed Greece and joined the war on the side of the Axis?" or "What if the USA went communist or fascist?" Even the leaders of these nations change... Charles Lindberg or Eugene Debs as the leader of the United States? Yep, it can happen in this game. Despite the limited context (world geopolitics and warfare between 1936 and 1948) the game will rarely, if ever, be the same game twice.
The player can also "liberate" territories belonging to other nations. For example, if Italy is conquered, it can be broken down in to three new nations. The US can have the Republic of Texas and the Republic of California taken away from them.
Nations all have a geopolitical designation which prohibit the player from being too crazy... for example, the game won't let Neville Chamberlain wake up one morning and decide to attack Sweden. Historically aggressive nations like Japan and the Soviet Union don't have that problem, so they may declare war at will... which makes for some very, very interesting games.
Alliances and protectorates are modeled as well. The United States guarantees the independence of every nation in the Western Hemisphere. Turkey is a protectorate of Germany. Mess with any of these alliances, and the chips will start to fall.
The Bad
Well, for starters, it's possible to conquer the world with a third rate power like Albania or Portugal. Not to besmirch the good names of Albania or Portugal, but the reality is that neither of these nations could conquer Germany, France or Russia on their best days.
Nationalism is modeled by the amount of dissent in each conquered province. However, the leaders of the nations themselves don't seem to mind losing a large swath of their territory and sign a peace treaty signing away those provinces after a year-long war... For example, fifteen Mexican units can lop off a huge chunk of the southern United States (and maybe even take DC) before the Americans can mount a decent defense... But instead of reconquering those lost territories, FDR seems to be as equally inclined to write off Texas, Arkansas, Oklahoma, California, Kansas, Colorado, New Mexico and Arizona in order to achieve peace.
The Bottom Line
All in all, this is a well-polished, well thought out game that is a must-have for fans of the WW2 genre.
