If you are still convinced that computer games are a flash in the pan, played only by the juvenile or the socially maladjusted, then this week’s two biggest titles should make you think again.

At a time when house prices are falling, food prices are rising and credit is all but unobtainable, Woolworths yesterday announced that 90 people a minute across Britain were shelling out £69.99 for Wii Fit, an interactive balancing board to complement the £170 Nintendo Wii consoles. The game’s trainer will assess your fitness, put you through your paces, and even chide you if you do not return to exercise regularly.

“This is a revolution in computer gaming,” said Gerry Berkley, Woolworths’ games trading manager. “For a game not targeted at gamers to sell in numbers like this is unheard of.”

The arrival of the high-tech fitness mat is also a further sign of how video games are becoming an accepted part of our lifestyles. While Grand Theft Auto IV is a thoroughly traditional boys’ own adventure, the Wii in particular has expanded the world of gaming to include women, previously poorly served.

Last week, a fortnight before the release of Grand Theft Auto IV, this week’s other mega-game, 15 million people had downloaded its high-definition film-style trailer. By the end of next week, the title will have sold six million copies around the world. It would sell more, but all initial stock has already sold out. Games technology is now so advanced that it can take players beyond the linear structure of films or novels. A well-written game can leave you free to explore its world. You create your own narrative. Grand Theft Auto IV offers such a wealth of distractions in its meticulously recreated 3-D map of New York that it is possible for no two players’ experience of the game to be the same.

It’s not just hardcore gamers who are excited by the possibilities. Steven Spielberg has been filling in the time between takes on his new Indiana Jones film by developing three new game titles for Electronic Arts, the world’s biggest computer games company. The first of these, Boom Blox, will be released in early May. Boom Blox is a puzzle title for the Wii and, like many Wii games, the emphasis is on fun. Spielberg’s game is based around players controlling a series of animated blocks and clearing the screen. GTA IV, meanwhile, is at the darker end of the scale, its high-definition graphics and motion-capture technology used to create a world that feels real.

For the first time in the short history of video games, consumers have a whole spectrum of experiences to choose from, a game to suit their every mood. And people wonder why TV viewing figures are declining . . . Wii Fit and GTA IV are reviewed in Knowledge today