I own it and have played it for a little while now. If you are a fan of the HOI series, then you will enjoy this. If you enjoy playing very large and complex RTS type games, you should enjoy it as well.
You are given control over a country (Argentina if you would like =) and guide the country through various means to start or join in on WWII. Events may or may not occur so each playing of the game may be a little different. You have control over the movement of your troops, but the only way to can influence the outcome of a battle is through your technology upgrades and the amount/kinds of units you move into a particular engagement.
There are a few bugs which are affecting the game play a little, but nothing too major. One thing Paradox is well known for is continuously patching the game based upon feedback from the community. If you are interested and wait a few more weeks (until the 1.2 update is released) I bet it will be a pretty solid product at that time.
I really enjoy it, but then I really enjoy these kinds of games.
Hope this helps,
-Groo