This download only product picks up where Hearts of Iron II: Doomsday left
off. Smaller in size and substantially smaller in price, Armageddon will
include two completely new alternative history scenarios, perfect for those
looking for new challenges! The scenarios will also have variable end dates
and in addition to a variety of new game options, gamers will find new
features like:

- New attachments for Naval units; do you scrap or upgrade those old ships
- Land units can now be built with brigades already attached.
- An Air Naval combat system that radically alters the combat balance
- New damage algorithms for the Air combat system, making organization more
important and allowing air units to fight longer.

http://www.paradoxplaza.com/index.php?option=com_content&task=view&id=163&Itemid=200