Many like war-based historical games and puzzles

Nicknamed "grey gamers", they are buying the more diverse games around, like strategy and historical titles.

"Because of the breadth of games now with more universal appeal, they are more enjoyable and social these days," said Codemasters' Richard Eddy.

The games company see the trend as a "natural evolution" for silver surfers who have become more tech-savvy.

Grandma Croft?

Codemasters found out there was a huge audience of "grey gamers" when they profiled the age ranges of users on their website.

"Over 50,000 ticked the over-35 box, so we contacted a few websites and local papers to say we would love to hear from more mature gamers."

They had over 250 e-mails from older gamers who enthused about their electronic hobby, usually associated with the younger generation.

The type of games that get grannies and grandpas going are the ones that require lateral thinking and problem-solving rather than shoot-em-ups, apparently.

Just as there are people who mis-spent their youth in snooker halls, now they are spending their middle age in Mario land Emma Soames, Saga How tech-savvy do kids think grandparents are?

Others which focus on football management skills, snooker and Great Escape-type adventures are also popular.

"They find it a very creative use of their leisure time, something that contributes to their active environment," Mr Eddy said.

And as technologies get more familiar and consoles find a permanent home by the TV, gaming becomes something the whole family can do together, said Mr Eddy.

June and Raymond Gill, 75, see no harm in it and regularly exercise their thumb action on game pads.

"We've been playing for 15 years, having been introduced to computer games by our son," said Mrs Gill.

"It keeps your brain active and we spend about two or three hours playing most days."

Mis-spent age

But some worry it is a sign that older people are becoming increasingly isolated.

"It seems to me that computer games are repetitive, isolating, and all the evidence is that older people need to be stimulated and challenged.

"I can't see this as a way of doing it," writer Jill Smith told the BBC's Today programme.

Instead of being a sociable activity, Ms Smith said playing games could simply be replacing watching TV alone.

Emma Soames, editor of Saga magazine said it was no different to knitting or playing card games.

"Just as there are people who mis-spent their youth in snooker halls, now they are spending their middle age in Mario land," she said.