One year after it was first announced, Microsoft has finally revealed the first full version of its Age of Empires Online game.

And if you’re a fan of empire-building Civilization-type games, or real-time strategy in general, then there’s good news: Age of Empires Online will be free to play indefinitely, with no subscription fees to worry about.

The core plot is a familiar one. The game launches with your small village (Greek or Egyptian, your choice) all alone in a huge online world. But by collecting resources, managing buildings and units, and improving your technology you’ll soon be able to expand, and so begin the process of transforming your civilisation into a powerful empire.

There will be plenty of other players trying to do the same thing, of course, and the program integrates with Games for Windows Live to help manage the social side of this. You’ll be able to chat with other players, trade with their cities, or perhaps send your armies to trample them into the dust: it’s really your call.

Initially, though, there’s nothing too exciting to do, probably wise as it helps new players learn how everything works. For the most part you’ll be engaged in simple “quests”, mini-missions where you need to perform some basic task: go here, collect that, kill the invaders, destroy their settlement and so on.

As you construct new buildings, build new units and begin to move along the technology tree, though, so Age of Empires Online becomes more interesting. And if you want more, then purchasing optional add-ons will deliver everything from decorations for your capital city, to new units and greater production capabilities, and more complex missions like the Defence of Crete (assist King Minos by fighting back hordes of invaders).

But while these add-ons are fun – and some may be essential if you want your empire to thrive – they’ll cost from around $5 to $20, which soon adds up. And while purchasing a Season Pass will get you all online content for 30% off the regular price, that’s still around $100 for just the first six months (and that’s a “special deal”: expect the price to climb even higher in future).

Of course you don’t have to pay out for the premium content. And while that may leave you at a disadvantage in the long term, there’s still plenty of fun to be had here. Just be sure you install Age of Empires Online somewhere with a fast broadband connection, though – installation involves downloading more than 2GB of data, so if your connection is normally on the sluggish side then you could be waiting quite some time.