GAME OVER By David Sheff (Random House/Hodder, $245) THIS is a book for Americans who believe that paranoia is a game all the family can play. Tired of wondering about the Japanese invasion of the car and property markets? Try worrying about the toy business instead. You will be aided and abetted by a blurbfrom the Invasion of the Body Snatchers school of business writing, and the undoubted fact that Nintendo products have been very popular in the Home of the Brave. For those of us who are not sure - or do not care - if the Japanese are taking over America, there is also much to enjoy. Mr Sheff has the priceless gift of being able to catch the excitement of business: the uncertainty, the effort, the suspense, the clash of personalities. He can read a balance sheet, of course. But to make a success of this kind of book you also need to be able to catch the flavour of a wet weekend in Seattle, particularly when experienced for the first time by someone who expected to spend her married life in Kyoto. Much suspicion - not all of it honestly motivated - has been cast on the success of Nintendo in the American market. Explanations range from ''a scorched earth policy'' by the particular company to general suspicions of Japanese skulduggery. It is a partof some people's world view that any playing field on which the Americans are not winning is not a level playing field. Conspiracy theorists can relax. Clearly the main ingredients in Nintendo's success are traditional and familiar items like a lot of hard work and some good decisions. That is not to say that the video game business is run like a branch of Santa's North Pole workshop. It seems that the level of ferocity displayed in any business is inversely related to the harmful possibilities of the product. If Ruritania decides to buy your bombers instead of mine, I can afford to be generous - the country's six potential enemies will all be likely customers for my fighters. Cigarette salesmen are carefully polite about rival poisons. While there are addicts there is always the hope that they may switch brands. The salesman of toys has no such consolation. In the toy business no prisoners are taken. No doubt this is the natural response of thousands of adults finding themselves at the mercy of the whims of millions of capricious infant consumers. Readers will have to judge for themselves - Mr Sheff's account is admirably objective - whether Nintendo has committed any crime more serious than winning. American readers may care to ponder, in addition, whether their economy really benefits from the popularity, as modes of business competition, of the Congressional inquiry and the spurious law suit. This book is a history of an industry, and a very peculiar one, which has many lessons for all of us in a rapidly-changing world. The video game had no antecedents. The first on-screen ping pong game had obvious possibilities - it was more lucrative than a jukebox and took less space than pinball - but the trick was to see where those possibilities would lead. One line of descent led to the video game parlour, one to rather expensive and elaborate games which allow you to fight World War II on your home PC. There were possibilities which flickered but never really caught fire, like four-person video games built into bar tables. The people who found the crock of gold were those who saw the future was a simple dedicated computer for children to play with. This humble possibility was the one with real money in it. Mr Sheff writes perceptively and well about the way in which Nintendo turned what might have been a temporary sensation into a long-term business, courting their little customers with magazines, free advice and a steady stream of interesting new games. Clearly the company has made a great deal of money. Most of this would otherwise have gone into Barbie dolls, fighting turtles, plastic revolvers, playdough, popguns or whatever. It is a funny market. Nintendo has certainly added a bit of colour to the scenery. My favourite character in this book is the Godfather of the operation, Mr Hiroshi Yamauchi. Mr Yamauchi has - and I dare say carefully cultivates - a reputation as the kind of capricious senior samurai who figures so prominently in the past roles of Toshiro Mifune. There is a wonderful scene (Mr Sheff has a good ear for anecdotes) in which he explodes over a roomful of Americans in an outburst of angry Japanese lasting several minutes. In the ensuing shocked silence the interpreter could be heard essaying a tactful rendition into English which started ''Mr Yamauchi is unhappy. . .''. Yet Mr Yamauchi regularly picks out the sort of artistic maverick who can compose winning video games. Though his own idea of intellectual amusement is a strenuous workout over the Go board he has an uncanny knack for picking out games which will be a success with children - even children thousands of miles away in a different culture. He is a man who would no more dream of showing an emotion in public than of exhibiting his private parts. Yet many of his employees are clearly devoted to him. Life is full of surprises. This book is one of the pleasant ones.