Development of Io has been cancelled. The first version can be downloaded though. Io is a puzzle platformer with a unique mechanic; a clay gun that can add and remove geometry in specific areas on each levels. The clay gun is used to solve puzzles throughout the game. Io is developed by three Swedish college students.
The first version showcased. Done as a school project. This is the puzzle platformer version shown in the earliest screenshots. It consists of three levels. It is the oldest, but most playable version. :)