Gratuitous Space Battles Available on Steam

A massively-singleplayer hybrid of RTS and tower defense
Positech Games announced today that Gratuitous Space Battles has been released via Steam, priced $22.99. Gratuitous Space Battles is a strategic space combat game where you design spaceships from modular components, assemble space fleets to do battle against your enemies, then observe just how well or how badly your fleet performs against a host of enemy fleets. Visit the official website for details - a playable demo is ocally mirrored here.