Swing a sword

At its news conference in Los Angeles, Nintendo was at pains to stress its different approach to games.

"What we are unveiling is the next leap in games, where gaming is not about looks but about feel, when gaming is not about the few but about everyone," said senior Nintendo executive Reggie Fils-Aime.

Rivals Sony and Microsoft have been pushing computing power and high-definition graphics. By comparison, the Wii seems under-powered.

Nintendo's focus is on how the controller for the Wii could attract new people to games.

Instead of offering a bewildering array of buttons, the controller looks like a TV remote and contains a motion sensor

Nintendo showed how it could be used to play tennis, steer a car, aim a gun or swing a sword.

New Mario

Among the working games demonstrated was a new instalment of the Legend of Zelda series, called Twilight Princess.

"This is by far the best Zelda game we've ever made and the most beautiful Zelda game we've made and it will be there on launch day alongside Nintendo system," said Mr Fils-Aime to whoops of approval from the audience.

Two versions of the game will be available, one for the GameCube and another for the Wii which takes advantage of the motion-sensing technology.

Nintendo also showed trailers for other Wii games, including a new Metroid Prime title and a new Mario game.

E3 attendees will be able to play a total of 27 Wii game demos to try out the new controller for themselves.

Nintendo is hoping the experience of playing the games will win over sceptics who may have doubts about the new controller.

End of the year

Key questions about the Wii were left unanswered. Unlike rival Sony, Nintendo do not reveal how much its console would cost or when it would be available.

"We believe it's in our best interests to keep the details private for just a while longer," said Nintendo executive Reggie Fils-Aime.

"We will give you more fun for less money and you will be playing Wii in the fourth quarter of 2006," he added.

Nintendo did provide a few more nuggets of information about the Wii. A low-power mode will let the console remain online to receive alerts and downloads.

And the main controller will contain a small speaker to play sounds happening close to a player in a game.

Alfred.Hermida-INTERNET@bbc.co.uk