World of Goo is a physics based puzzle / construction game. The millions of Goo Balls that live in the beautiful World of Goo don’t know that they are in a game … or that they are extremely delicious. Using your Wii Remote, you take control of these goo balls (many of which feature different abilities), pick them up and connect them together in order to construct jiggly architecture — bridges, straightaways, makeshift high-rises, even — so that you might lead other goo balls to an exit situated on one end of every stage.
The demo contains the entire first chapter (20 per cent of the game).
There is also a free mini-game called Tower of Goo you may wanna check also..