Even though tower defense games seem to be perfect for digital distribution platforms, Xbox Live Arcade only has one: the lazily-ported Crystal Defenders. Well, Hidden Path has more than made up for the genre's poor showing on XBLA and delivered one of the very best strategy games around in Defense Grid: The Awakening. Available on PC since last December, this is a highly polished effort that stands out in an overcrowded genre. Plus, at $10 it's half of what the PC version costs and includes bonus maps. No strategy fan should overlook this one.

Tower defense games task players with building sentry guns that will shoot down incoming hordes of enemies. Instead of having direct control of the action, you'll need to think strategically and plan ahead so your towers can do the dirty work for you. The story is minimal, but it's more than we usually get in these sorts of games. In the distant future, aliens have all but wiped out the human race. In order to send the crustaceans packing you'll need to activate the titular Defense Grid and save the planet. To help you out with strategic advice, alien data, and friendly encouragement is an affable computer AI with an adorable British accent. He used to be human, and lost the battle against the aliens 1000 years ago. Over the course of the campaign he'll flesh out the story and lend some...