Io is intended to be a highly replayable, easy-to-learn but hard to master roguelike in the spirit of Spelunky of all things. It is set in a surrealistic alien world and will feature a dynamic environment, intelligent monster AI and a versatile item system.
As per:
http://www.indiegamemag.com/witness-fully-destructible-procedurally-generated-3d-dungeons-in-io/With the official blog entries:
http://iogame.tumblr.com/ "roguelike 3D platformer with fully destructible and editable procedurally generated voxel levels(*breathes*)."
The Indie gaming mag article outlines the details and has the latest video, really well done stuff this small team is managing.
2012 is heating up indeed!