Not long ago, we got some details and screens about Tetris Party, a multiplayer Tetris game for the Wii that, among other unique features, supports play using the balance board.
http://www.destructoid.com/tetris-party-gets-fall-wiiware-release-with-balance-board-support-97401.phtml

People who have followed my on-again, mostly off-again, but now it’s on-again blog know that the concept of playing Tetris for the sake of physical activity is nothing new. Roll the clip..

Since Tetris really only requires 4 inputs from the player (move right, move left, rotate and drop), it is relatively easy to map these inputs to movements; and pretty easy for a player to understand.

I would have liked them to map the balance board to the same input as the nunchuck analog stick. That way you would instantly have a load of backwards compatible games to at least try with the balance board. But I digress…

The webcam game shown here – TetroDance is now free at http://JackGames.com if you want to give this concept a test run. Needless to say a webcam is required.