Atari has announced a new action RPG for XBLA, Gamma World: Alpha Mutation. It’s being developed by Bedlam who are behind the recent D&D Daggerdale. The game is set on Gamma Terra, a world which is the product of multiple universes merging together thanks to an experiment gone wrong at the Large Hadron Collider.

Gamma World is a third person shooter with RPG elements, offering a bunch of character customization (think half-android half-yeti) and allow you to play online co-op (or two player local) with up to three other players. The titular Alpha Mutation will allow your character to evolve over time and you’ll also be able to construct new weapons, armor and other items from parts scavenged throughout the world.

Expect to see Gamma World on XBLA in the fall of this year, we’ll keep you updated on new info as we get it.