Then came Age of Empires Online which, if you didn't know, . The game is completely free to play but offers a variety of addon content for those who want to extend their experience. Addon civilizations are available for $20 each, "booster" packs with new game mechanics are available for $10 each and there's a "Season Pass" giving players access to all content for the next 6 months at 30% off the usual price. "Don't take this option if you're not single," said Microsoft's PR representative, warning players of the dangers of getting too involved in a game without making an effort to get their partner hooked too.

Halo Anniversary was on show but in the limited time available I couldn't get near it -- and the same was true for Gears of War 3.

I did, however, get the chance to try an interesting upcoming Xbox Live Arcade game known as Orcs Must Die! Casting the player in the role of a heroic figure who must defend a crystal from incoming -- you guessed it -- orcs, the game blends tower defense, shooter and action combat together into a satisfying whole. It's a little uncomfortably similar to Trendy Entertainment's , but Orcs' single player focus and lack of more traditional RPG elements makes it a more different game than may appear at first glance.

Microsoft, then, certainly has plenty of great titles in the pipeline, and looks set to have a very good holiday season. Most of the games on show aren't available as yet, but you can play Age of Empires Online -- and if you read a while back, you'll know that might be a good idea.

This article originally appeared on GamePro.com as