Game collective Kokoromi announces the theme for its fourth experimental game expo, to be hosted at GDC in March.

The expo, the second of which was responsible for inspiring Jason Rohrer's Passage, started out being hosted during the Montreal International Game Summit, but will now begin with a party on March 10, during Game Developers Conference.

The theme for Gamma 4 is One-Button Games, an invitation to explore simplicity in the face of the new complexities of gestural, motion, voice and mind controls by creating games which use just one input. Think Digital Chocolate's horribly complusive Tower Bloxx - and beyond.

Previous Gammas have focused on games using no more than 256 pixels in width/height, 3D - here's Randy Smith's account of that one - and those driven by live audio.

Kokoromi itself comprises Phil Fish, the developer behind Fez, the winner of excellence in visual design award last year's IGF and a nomination for design innovation, Damien Di Fede, Heather Kelley and Cindy Poremba.

To find out more about the event and how to submit, visit Kokoromi's site.