Jeff Koons: King of comic relief

The Serpentine's summer blockbuster is an exhibition of kitsch masterpieces from the American artist Jeff Koons. Michael Glover doesn't know whether to laugh or cry

What a mind-numbing spectacle have we here! This summer, the Serpentine Gallery, those staid former tea rooms in Kensington Gardens, has been transformed into something that at first glance seems to have more in common with a cross between Las Vegas and Blackpool Pleasure Beach than a public art space for the usual gang of slouch-shouldered, frowny cerebrals.

Here you will find a riotous mixture of ready-mades and replicas of plastic toys of the kind you might find flung around a suburban pool and, on the walls, zappy, computer-manipulated images of soft porn and Popeye, with a few high-minded cultural references thrown in to add just a touch of spice to the mix. The juxtapositions are violent and strange enough to please even a proto-Surrealist such as the Comte de Lautréamont, who wrote, in 1869, of "the chance meeting on a dissection table of a sewing machine and an umbrella..."

The ready-mades include a step ladder, a stack of plastic chairs, and a rubbish bin. A brightly spotted lobster hangs in the air upside down like some circus strong man, supporting himself between a tippling chair and a wonky rubbish bin. Elsewhere, jug-eared monkeys with brightly slashed cartoon smiles hang down from the ceiling, lazily locked arm to toe. Inflatable beach toys lie around – or hang around from ferocious meat-hooks painted in gay yellows and reds. A multi-armed caterpillar with a green head and sweet, doey eyes eases its way between the rungs of an aluminium step ladder. A dolphin makes a mighty, arcing leap through the air. A noisy gaggle of pots and pans are suspended from its underside.

These over-size pool-side inflatables and children's toys are not the real things, of course. They are beautifully, painstakingly made replicas, usually in stainless steel and aluminium, polished and then painted, faithful to every last crease and fold of the original plastic. Amid all the kiddy mock-innocence there are lots of side glances at S&M and raunchy hetero sex too – most of the inflatables are painfully worming their way through mesh of one kind or another. The artist from whose studio all this stuff has originated is an American showman called Jeff Koons. Yes, loony Koons is in residence in London all summer, presenting for our delectation a group of works loosely tied to the theme of Popeye and his gang of late-1920s miscreants. It is not only Popeye, exactly 80 years old this year as it happens, who is being remembered here. The works make many other references to the heroes that populate Koons's pantheon – Salvador Dalí, Marcel Duchamp and, more generally, the Surrealists and the Dadaists, with their zany humour.

Sometimes it is quite difficult to know whether to laugh or to cry at the work of Jeff Koons. It seems utterly preposterous, almost beyond the most absurd critical joke, that anyone should take this stuff seriously at all, or have the gall to stick the label of art on it. And yet they do, and the buyers come flocking. In 2007, Hanging Heart, made out of stainless steel, sold for $23.6m. The powerful collector Francois Pinault is a big buyer. Koons's Balloon Dog – a giant, stainless-steel version of the kind of dog that Uncle Harry would have made for you at your seventh birthday party, twisting it up and about, if you had had the presence of mind at such a tender age to hand him a long, partially inflated balloon – stood outside the Palazzo Grassi, overlooking the Grand Canal, when that museum opened in 2006. At the moment, Koons is overseeing the fabrication of a giant replica of a steam train, which will be complete, when it's finished, with intermittent chug-chugg-chuggs and woo-woo-woos. It carries a price tag of $25m. Some museum on the East Coast of America is said to be hyperventilating at the prospect.

Down in his studio in Chelsea, New York, Koons employs up to 100 studio assistants at a time, making all those stainless-steel replicas of inflatable toys with such loving care, beneath Koons's ever-attentive eye. Yes, he really cares about the idea of the perfectly burnished finish. But, really, what is the point when the work itself seems so fatuously pointless, so mind-numbingly tasteless, and so utterly superficial? And yet Koons himself does not see his work as tasteless kitsch at all. In fact, he is tremendously high-minded about it, always, almost messianically so. He takes himself tremendously seriously. The argument that he regularly deploys in defence of his artistic practice is as follows. My art is all about democracy, he preaches. The general problem with art is that people feel intimidated by it. They feel set apart from it, inferior to it. Koons wants to get rid of all that kind of old-fashioned guilt by making an art that is readily approachable, understandable and enjoyable. He wants to be entirely non-judgmental. He doesn't want people to have to feel that they are nervously looking up at something that they don't quite understand. He doesn't want people to have to think and worry about pesky things like meaning. What you see is what you get. Koons brings us all together, in one big happy family. He makes us feel good about ourselves in the presence of art. Here is how he puts it, in a nutshell: "They don't have to bring anything with them other than exactly what they are, and they're perfect for that experience because it's about them..." So: no training; no thinking; no work. Who needs a critical eye when you, the all-important one, are already empowered from the moment you walk in the door?

Can this grown man really believe such tosh? Koons grew up in a small town in Pennsylvania. His father owned a furniture store. Young Koons admired the way furniture got displayed – lighting; positioning; juxtaposition. His father, as Koons confided to us at a press conference this week, taught him everything he needed to know about aesthetics. The young man also sold candy door-to-door to earn some pocket money. Koons himself, now 54 years old, with short-cropped hair and a ready smile, talks like a compulsive salesman for his own product. He's eager-looking, boyishly optimistic. What he says is often not quite comprehensible, but it sounds good, until you think back at what he has said and wonder, sheer banalities aside, whether it really means anything much at all. He is especially fond of the word transcendental. "Art is a vehicle that connects you to human history," he says. "I want people, when they look at my art, to have engaging moments. I want them to feel that everything about their lives is perfect – their history, their culture, their selves. Everything is in play. Everything is possible..."

Are these the statements of a man who is a serious artist? Or are they the easy bletherings of a flattering trickster? Up on the wall behind him, multiple computer-manipulated images of Popeye were swelling their engorged biceps in readiness to pop yet another can of spinach, and mouthing, "I yam that I yam that I yam..."

Jeff Koons: Popeye Series, Serpentine Gallery, London W2, Thursday to 13 September (020-7402 6075; www.serpentinegallery.org)