If you caught the video the other day, TVShow developer Rudy Huyn has demonstrated how powerufl the new Live Tile system in Mango is by creating "an app without an app". Specifically he created a Tetris game using just Live Tiles, which is pretty awesome.
Though he has no immediate plans to actually make this into a game, he will make the code available so others can get some ideas and hopefully innovate.
In this new video, we see he now uses the Zune controls for movement of the Tetris shapes, which seems a bit nicer and over all game play (if you can call it that) looks smoother.
Source: YouTube; Thanks, Rudy, for the heads up