It's one of the world's most simple computer games - but, as a new report suggests, there could be more to Tetris than the idle act of fitting blocks together on a computer screen.
Computer games have changed beyond all recognition since those early days when blocky graphics would judder across a screen and explode with all the sonic impact of an egg box being crushed.
But while most of today's new games boast the production values of a Hollywood blockbuster, a handful of old favourites continue to defy their apparent sell-by date. There's Solitaire, the card game that comes pre-installed on every version of Windows.
And then there's Tetris, the creation of a Soviet computer programmer which requires players to move different shaped blocks into position so they form a straight line and then disappear from the screen. Despite its minimalism, this year Tetris celebrates its 25th birthday.
But while Tetris continues to win over new legions of entry-level computer gamers, it's also been drawing the interest of brain scientists. Some even suggest the game may actually be good for the health of the mind if not the body.
While hours spent struggling to sink those breezeblocks render fingers sore and gnarled, there are scientific studies that point to wider benefits.
The latest inquiry comes from the Mind Research Network (MRN) - a brain research organisation based in the United States. Using little more than MRI brain scanners and game consoles, scientists have found that regular turns on Tetris caused the grey matter in a group of teenage girls to thicken.
Earlier this year, Oxford University reported that Tetris could reduce the flashbacks experienced in post-traumatic stress disorder (PTSD).
In the research published this week, 26 adolescents were asked to play Tetris for 30 minutes a day over a three-month period. Their brain power was then compared with a similar group who hadn't been playing the game.
The theory is that Tetris thickens the cerebral cortex - part of the brain that plays a key role in memory, attention, perceptual awareness, thought, language and consciousness.
"What we found was a change in the brain after playing Tetris," says Dr Richard Haier, a neurologist who led the project. "The thickness of the cerebral cortex actually increased, by less than half a millimetre.
"It used to be thought that the number of neurones [brain cells] in the brain was fixed after a certain age. This appears not to be true."
It's not the first time Dr Haier has seen research potential in playing Tetris, initially discovering the game in the early 1990s.
"Back then we were trying to find out what happens if you practise something over time. We suspected that the brain efficiency was the key concept.
"I was looking for a game that was suited to look at what happens to the brain when you practise a complex task. In 1991 no one had heard of Tetris. I went to the computer store to see what they had and the guy said, 'here try this it's just come in'.
"Tetris was the perfect game, it was simple to learn, you had to practise to get good and there was a good learning curve. Tetris is an excellent tool for neuroscience."
The link between computer games and boosting brain power is not new. Leading software companies like Nintendo have created their own brain-training games, such as MindFit, IQ Academy and Anagrammatic. These claim to sharpen up mental processes like memory, visual spatial awareness and concentration.
But the apparent benefits of Tetris or other such games only go so far. What scientists have so far failed to find out is whether the new mental powers learnt from playing Tetris can help with anything other than... playing Tetris.
"The $64,000 question is whether these brain changes are beneficial to activities other than playing Tetris. They are very important questions about the brain and learning."
Dr Chris Bird, a clinical neuroscientist at UCL, is cautious should anyone think Tetris is a short-cut to becoming brainier.
"If you practise something you are going to have to engage your brain in some way. By doing something again and again the parts of the brain involved in that operation will change," says Dr Bird.
"It's the same with tests on cab drivers in London who have to do the Knowledge [memorise every street in the capital]. These studies also show a decrease in other parts of the brain.
"So while some parts of the brain show an increase in cells, there's a cost."
And one thing that Tetris doesn't seem to help is visual perception. Dr Bird cites a study from 2003 which assessed the benefits of action games, or "shoot 'em up" games, and found they helped improved a player's visual perception. In that research, Tetris was played by the control group - and those who played the puzzle game had not notably improved on the tests.
So what about hardened Tetris players themselves - do they see any knock-on benefits in other parts of their life?
Waste of time
Vincent Laurent, a member of harddrop.com, an online community of Tetris addicts, has been hooked on the game for 17 years. He said the attraction for him is its deceptive straightforwardness.
"Under a really simple and easy appearance, the game is incredibly deep and complex, it needs many years to assimilate every combination and keys to solve the problem.
"Today we have some versions of Tetris game which require five years to be finished, there is no more harder video game in the world than Tetris Grand Master 2 and Tetris Grand Master 3."
After spending much of his life glued to Tetris, Vincent, who is French, is in a strong position to judge whether it improved his mental skills.
"Honestly, with the level I have reached today, I prefer to think that I wasted my time," he laughs.
"I am sure it doesn't improve anything in the brain, except the Tetris skill itself. I can play today at more than three pieces per second, but I am slow in life, slow and a perfectionist. Tetris never helped me to think better or faster unfortunately."
Below is a selection of your comments.
I have used the art of Tetris when filling my freezer- it is quite astounding how much can be fitted in.
Leeanne, Suffolk, UK
I'm 16 and I grew up playing Tetris, in a generation where most of my peers were obsessed with the latest Pokemon game. I love a good game of Tetris on my mum's classic Nintendo Gameboy (yes the one that needs 4 AA batteries and looks like a brick), however uncool and out-dated I may seem. Tetris is amazing - FACT.
Lizzy, London, UK
Re "thickens the cerebral cortex" - all very nice, but there is a significant part of the neuroscience community who have follow the theory that the reason cortex becomes thinner with age is that it is becoming more organised and specialised, and removes unwanted connections. So if the cortex becomes thick again, this might just mean the cortex is becoming more DISorganised - not necessarily a good thing.
I worked for two years in a town north of Kenya in a flight planning and control office where we managed 30 aircraft to transport relief to Sudan. Initially I was not good with making flight manifests but I think Tetris may have played a role in improving my flight planning skills. We would compete on Tetris every day for two hours. It was exiting and you had to think ahead and concentrate. By the time I left the flight office, I was a master planner of manifest.
James N Mugo, Kampala, Uganda
While waiting for the loo in the dark during a long, overnight flight to Japan I remember looking out over the passenger cabin and seeing almost every passenger playing Tetris on their seatback TVs. It was a surreal sight.
Ian, London, UK
I used to use Tetris to speed up my thinking and to help me relax before sitting exams. It seemed to work.
Jay, Cardiff, UK
I love the line in this piece that says they used "little more than MRI brain scanners..." Little more? Surely MRI scanners are quite a big deal. If the line had been "little more than an old cereal box and a pair of toilet roll tubes" then it might have been appropriate.
Martin, Maidenhead, UK
What a great game. I remember reading a review when it first came out which stated that it was "fiendishly addictive", and although I haven't played it for some years, I can't say that I disagree. I might try and find a copy again, but then does my wife really aspire to becoming a Tetris-widow...
Pete, Didcot, England
I went through a phase of playing Tetris a lot when it first became popular in the early 90s. When I fell asleep at night, Tetris blocks would appear to fall inside my eyelids. I stopped playing soon after.
If Tetris is thought to affect the grey matter, presumably that might mean other games do likewise... but to their detriment or benefit? We hear of certain games bringing out aggressive behaviour and others where people get so hooked they have literally died because they can't leave the console.
Alex, Edinburgh, Scotland
Excellent, just the justification I need for the hours I still regularly spend on my ancient Gameboy playing my favourite game. Even after a few months cold turkey, it doesn't take long to get back up to speed. Surely further proof that it's a vital life skill.
I recently completed 150 levels of Tetris on the mobile phone version of the game and I can see no improvement in my intelligence at all. Echoing what Vincent Laurent says, the only improvement I have experienced is that I am better at Tetris than when I started. Personally, I think the whole story is overblown and any increases in intelligence are so negligible as to be completely meaningless.
Daniel Penn, Bradford