You couldn't call her subtle, but Annette Messager has fun. Perhaps fun is an odd name for work that has plenty of agony and aggression and anarchy and other serious-sounding things. But the extravagant way in which they're delivered lightens them up a lot. Fun, in the sense of spectacular entertainment, becomes the dominant note of her art and what sticks in your mind afterwards.
Annette Messager is a famous French artist, born in 1943. You ought to know her, except that she's been little seen in the UK, and this show at the Hayward Gallery is her first proper showing since a touring exhibition in the early 1990s. If her sculpture seems familiar, it's doubtless because there is an overlap with the needlework element of Louise Bourgeois' work; indeed it shares some of her general rhetoric of pain. If you like Bourgeois, you should definitely get along.
This is a swift retrospective, but it manages to include some of her major pieces. The earliest exhibit comes from about 1970 and sets the tone. Simple enough: glass cases are filled with rows of poor little dead birds, each wrapped in its woollen cosy. It's about the most flagrant bit of pathos I've ever seen in a gallery. It gives you an idea of Messager's very direct emotional key.
She speaks a language of victimisation, filtered mainly through the nursery and the Catholic church. The martyrdom of soft toys! She has a knack for imbuing stuffed objects and limp cloths with pitiful bodily sensations, and treating them like relics and ex votos. The furry innocents get massacred over and over. In piles, in scores, they are hung from the wall, dangled from the ceiling, caught in nets, strung up, pegged up, bound up, impaled on pikes.
So no, it isn't subtle. But since her cast of puppets, plastic bags and garments is also richly multi-coloured, there's a counter mood of carnival and ecstatic pleasure. That isn't subtle either, but it's a complication of sorts. Or take Glove-Face, a skull head, made of black knitted gloves which bristle with sharpened crayons poking out of all their fingers: soft, hard, blackness, colour, violence, sweetness.
Messager plays out these mixed feelings freely and without any particular focus. She revels in them, and we can too, but it's a technical exercise. Her art is heart-piercing in the way that a ghost-train is scary. She's staging a psychological funfair, and inciting the same demand in her audience for more. What kind of a ride will she come up with next? The answer is: some extremely inventive ones. In her recent works she creates a sequence of highly theatrical and surprising animated installations.
Inflated-Deflated fills a large area of floor with a variety of forms made of cushion-cover fabric – large body parts, internal organs, sea creatures – attached to pumps. A penis, a hand, a heart, a foetus, a mouth, an anemone, they all begin in flaccidity. Gradually they fill up with air, one here, one there, then puff out again. Finally they are all up, and inflating and deflating in a regular breathing rhythm – or rather, half of them swell out as the other half sink down, and then vice versa.
It's a metaphor for life. It must be – though I wouldn't try to make anything more out of it. Just enjoy this spectacle, and then move along to Casino, which begins with an even more startling device. Wind action, again. It's like the moment in The Shining when the lift opens and an ocean of blood rushes out. Here, through a doorway, we see a raging turbulence of scarlet silk – and then a great carpet of this silk is suddenly blown up, billowing, flooding, towards us.
These shows work alright, sometimes brilliantly, and I was glad to see them done – not least because they're so alien to our own art scene. The "sensation" generation has often been accused of showmanship, but no British artist would indulge in Messager's level of theatre. They'd consider it impossibly vulgar, uneconomical, emotionally splashy.
Rebecca Warren is a British artist, born in 1965. She's a sculptor – that's to say, she works in the very unfashionable practice of clay modelling. A contemporary artist who squeezes, digs, extrudes and moulds the sticky stuff is not one you expect to see at the Serpentine Gallery. Or if you do, you expect some kind of a joke – certainly not that the medium will be taken seriously.
There is one obvious joke here, a piece that Warren made 10 years ago and became a signature piece. Helmut Crumb is two pairs of grotesquely sexed up women's legs plus crotch – the references are to the cartoonist Robert Crumb and the photographer Helmut Newton. Her earlier works developed overt ironies. They were like a rude parody of post-war figurative European sculpture – Giacometti, Germaine Richier – playing the distressed existential body up against "bunny girl" caricature porn. It was a bit stupid, but it had some potential. And that's materialising. The other sculptures here are mostly much more recent. Warren continues to handle the clay in its raw grey state, and show them on rough plinths, as if still in the studio. But these new works are deeper into their medium and making. They're more or less figurative, but in most cases much less. They have a default condition, which is an inarticulate, gunky lump.
Sometimes memories look short. Take the stacked-up bulbous body parts of The Other Brother or A Culture – Miro or Picasso have been there before, near enough. And modern sculptors have done many vivid variations on the mud pie glob: Lucio Fontana, Giuseppe Pennone, William Tucker. If that seems like too much name-dropping, then check them out.
Warren's eight vaguely upright blobs, called We Are Dead, do have life stirring in them. They sit there, unresponsive and obstructive – but something obscure is going on. Hints of flesh are taking or losing shape, appearing embryonically, vestigially. But the more important tension is between a sense of collapse and a sense of stance. Is a figure remotely drawing itself together out of this mess? Is there an entity in there, or just a slippage of surfaces?
In each one a sculpture is on the verge of existence, and though the things look crude the effect is quite elusive. Deliberate cack-handedness is in dialogue with improvised shape-making. This is perfectly traditional sculpture activity.
And next to Messager? Two body-sculptors: but the contrast hardly needs even stating. You can find wildness and excess in Warren's handling of clay, but compared with Messager's her art is a model of restraint. It operates in a tight register, where small gestures count. It values the laconic and the enigmatic. We Are Dead: what's it expressing? What does it mean? We can't quite say, and that's a mark of its seriousness. That what makes it good. And it's good too to see the difference displayed so clearly.
Annette Messager: Hayward Gallery, South Bank, London SE1; until 25 May; admission £9 with reductions (also admits to The Russian Linesman).
Rebecca Warren: Serpentine Gallery, Kensington Gardens, London W2; until 19 April; admission free