• by Steve Smith  @popeyesm, November 2, 2012

Continuing to break out of its decade-long role as the major online reseller, Amazon extends its mission to become a publisher into the mobile app arena this week. The first game app, Air Patriots, flew into the respective app stores for Amazon’s own Kindle Fire line as well as for Android and iOS. This variant of the tower defense genre (but in the air) is free to download and try but requires in-app purchases ranging from 99 cents to $6.99 to experience more fully.

The app is the second release from Amazon’s Game Studios, a unit of the company formed to craft apps across platforms. Its first title, Living Classics, was a social media game.

While the game runs across iOS and Android devices, part of the design shows off Amazon’s native game network only on the Kindle Fire devices. Much like Apple’s iOS GameCenter, Amazon’s version tracks in-game achievements and high scores. In this case the game also saves a user’s progress in the cloud so gameplay can be ended on one Kindle device and picked up on another.

The game initiative is just another example of Amazon moving more aggressively into the publishing arena. The company has recently initiated a number of e-book imprints as well as a digital video studio.