Stardock Entertainment has announced they will be launching a beta version of their new tower defense game, Siege of Centauri, on March 28th. Interested players can join the Founder's Program for $10 on the game's website.
According to Stardock, you will be able to take "on the role of commander of the defense of Earth's first colony on Proxima Centauri" with the ability to defend resources, deploy battle response teams, and call in reinforcements.