'What's The Point Of It?', 'The Hotel Room': A Dynamic Mixture of Art, Architecture, And The Abstract

That kind of feeling inhabits all of Creed's ongoing stabs at creation. His work is ordered simply, numerically, in the way that Prufrock was in the habit of measuring out his life in coffee spoons. Each piece, from the lump of Blu-Tack on a wall (Work No 79) to the blind paintings (eg Work No 1363), you imagine, seemed like a good idea at the time, got the artist's blood briefly up, but what you are often left looking at is the limp memory of that creative moment. Maybe that's how inspiration and its aftermath always feels.

The writer Nicholson Baker once argued that most decent thoughts "have about the size of a wardrobe and the complexity of a wheelbarrow". Creed's tend, on the whole, to be more diminutive than that. They are balled-up pieces of A4 placed like little shrunken brains in their display cases; they are literally one-note musical compositions; they are framed doodles and scribbles that don't aspire to anything; they are a thousand broccoli poster paint stamps, a superfood forest; they are doors opening and closing; they are the (Turner prize-winning!) lights going on and off in the gallery.

There is, as ever with ticket-holders-only minimalism, a very fine line between the mindfully simple and the simple-minded. Few artists have ever negotiated that squiggle in the sand quite as boldly as Creed. His ziggurats of old cardboard boxes, his displays of sporting balls of different shapes and sizes, his deconstructed ballet steps, his grim semi-improvised singing (there is an album to accompany this show), his little cubes of Elastoplast, his O-level self-portrait might conceivably be viewed as knowing, or innocent, or joyful, as fans attest. But you can't help feeling you might need quite a low bar for knowingness, a spotless mind for innocence, a Buddhist master's understanding of joy, to appreciate them fully.

The vague argument of this retrospective is that art, like life, is essentially an involuntary act: the rising and falling penis apparently has a mind of its own, biology is its own imperative. If you hadn't got that particular point, Creed dramatises it with video of a woman squatting to leave a turd on a gallery floor and a Technicolor film of a man vomiting in a similarly whitewashed room. Creed's belief, his credo, is that he "finds it difficult to make judgments, to decide that one thing is more important than the other. So what I try and do is choose without having to make decisions." In other words, for better or worse, anything he comes up with he gives a number to and adds it to the collection.

One advantage of never having to decide which is a half-cocked idea and which a fine upstanding concept is that when you eventually hit on a winner it stands out a mile. Creed's beautiful Scotsman Steps (Work No 1059), which link Edinburgh's new and old towns in treads of different marble, were one such piece (referenced here in the stripes of his walls and painted pyramids). His idea for three minutes of national bell ringing (Work No 1197) to mark the opening of the Olympics was another spirited piece of mood-capturing. And his room in which exactly half the air was contained in balloons (Work No 268) was the piece that rightly did most to make his name. A version of that room is recreated here, which you squeeze into with white balloons well over your head, to experience claustrophobia and childlike lightness in about equal measure.

In his concentration on the experience of the body in space, Creed often seems to be taking his cue from Bruce Nauman, who was painting himself black and juggling with his testicles way back in the 1960s; likewise, Creed's neon  signs ("Don't Worry" is included here in bold yellow) are a direct lift from the American. Where Nauman often deals in whispered alienation, however, uncertain whimsy is more Creed's inclination.