Microsoft has been secretly developing technology that lets people play videogames using natural body movements. The big idea is kill off the Nintendo Wii using a project codenamed "Natal," a system that combines cameras and voice and face recognition software to recognize people and their actions.

Movie director Steven Spielberg has been roped in to endorse the project. He said that the gamer in me went out of my mind when I got to be interactive with this.

Natal lets people play driving games by simply moving hands as if turning a car steering wheel. In-game characters in boxing, skateboard, soccer and other sports titles mimic the body movements. The system scans faces and voices to determine who is playing.

Redmond is not saying when the kit will be in the shops, but yesterday released a software kit for videogame makers interested in designing titles to take advantage of Natal's capabilities.

When it is released, it will change the way that people play videogames in the same way that the Nintendo Wii managed it. Only with Xbox graphics and no need for motion controllers it will be scarily interactive.

Don Mattrick, the head of Microsoft's Xbox and games business said that the kit will work on all Xbox consols.

Spielberg said the game could change the way stories are told.