It's awesome!
It uses a very lite rules set.
Hits depend on what you roll on special dice that come with the game that have symbols for every unit type on them.
The expansions are really cool because they change the theater of operations and add in units for the different axis and allies armies while keeping the exact same rules system as the base game.(sometimes they add in a special rule to give the armies flavor)
The base game starts you with a few really good scenarios that increase the number of rules you use until you are using the every rule in the game. (There aren't a lot of rules even then.) If you add two base games together or buy the Overlord box set with the core game you can have up to 4 players playing very large games for larger operations during the war. (Like Operation Overlord and Operation Market Garden) If you also invest in the airpack it adds very cool air rules to the game and updates the rules. (It isn't necessary but it's fun) I'd suggest the Terrain Pack, Eastern Front expansion, Desert/snow map, air pack and the campaign book. (which uses all the expansions mentioned to recreate two VERY large campaigns on the Eastern front out of scenarios that are interlinked by victory conditions.)
The base game is just fine by itself but most people I teach the game to end up buying the expansions as well. they add a lot of fun to the game and provide countless hours of extra gameplay.
Here is the board game geek page for the game which gives pictures, an overview and links to the individual expansions:
http://www.boardgamegeek.com/boardgame/10630
(I haven't ever really posted much on Dakka. Is posting a link to another site ok?)
Hope this helps.
