Is Maurizio Cattelan quitting while he’s ahead or before he lags too far behind? The question hangs over that Italian artist’s much anticipated 21-year retrospective at the Guggenheim, where, as is widely known by now, all the art is up in the air, too.

This unusual show has been described by Mr. Cattelan as his swan song. Although only 51, which is young in artist years, he has announced that he is retiring from the job of making art. Perhaps to celebrate, he has turned his retrospective into something of a final blowout artwork, one made of earlier pieces — 128 of them to be precise — and involving some delicate engineering. Mr. Cattelan’s entire artistic output, excepting two works whose owners declined to lend them, hangs in a gigantic distended mass from cables connected to an aluminum truss near the top of the museum’s rotunda. Titled “All,” it fills one of the most famous architectural voids in the world with what surely ranks as one of the largest, most complicated, visually muddled mobiles in the history of art.

It’s an impressive feat, Mr. Cattelan’s seeming evasion of the stultifying grip of the retrospective by “stringing up” his art — to use the words of Nancy Spector, the Guggenheim curator who organized the show, in its catalog. The effect is initially startling, but ultimately disrespectful and perverse. In some ways it may be just the thing for our attention-deficient times. You can zip up and down the ramp seeing everything and nothing at top speed. Yet its entertaining conceit aside, the show suggests that Mr. Cattelan knows what he’s about: he’s always been uneven and now he is running out of ideas. It may indeed be time for him to quit, and his previous, consistently subversive forays into gallery-running, exhibition-making and magazine publishing give him plenty of options.

The self-abnegating spectacle of “All” is completely in character with Mr. Cattelan’s well-known ambivalence about himself, his talent and his art, and his oft-cited fascination with failure. He grew up in Padua, the son of a truck driver and a cleaning woman. He worked from an early age; the biggest impression was made by a stint in a local morgue, an experience that Ms. Spector cites as a source of the continuing fascination with death most evident in his recurring use of taxidermied animals. He backed into art with little formal training after working briefly as a furniture designer.