It’s not every day I give an art exhibition a G rating, no less a Serpentine Gallery exhibition, known for its esoteric shows with a strong adult nature. But the launch last year of the Serpentine Sackler, a sister gallery in Hyde Park, seems to have given the august London institution a new lease on life.

Kids, I am told, are welcome to observe and even interact with the art at the Sackler’s Julio Le Parc retrospective, open now through February 15. “The ideal spectator is the most free, most open, least conditioned,” Le Parc says of the current installation. “The most important thing for me is that brief moment of interconnection.” When some of these works appeared last year at the Palais de Tokyo in Paris, Le Parc spoke of his disdain for passivity and ideological conditioning and his quest for a more reflective, analytical, creative viewer. You get the feeling he could think of nothing worse than a gallery full of sober aristocrats, hands clasped behind their backs.

The Sackler presents an entirely different experience. It’s free admission, though I would have lined up for tickets like a kid at a fairground, which is virtually what this show is. There’s a spinning wheel with Op Art stripes you can whirl as if you were a Price Is Right contestant; a dozen pairs of boldly colored glasses with visual effects created by mirrors around the lenses; a wobbly floor with a Space Hopper tethered over the center, taunting you to stagger up and punch it; a vibrating mirror; a pitching target cut in exaggerated silhouettes, or “myths.” These pieces date back to 1960s Paris, when Le Parc was creating work with fellow activists from the Parisian Groupe de Recherche d’Art Visuel (GRAV) that challenged the art establishment with its immersive installations.

Ever since, the 86-year-old Argentine has been concerned with the artist’s role in engaging the public. Through this interactivity, the viewer learns to think with a broader perspective, discover new ways of interacting with the wider world, to see the “we” before the “me.” It’s no wonder Le Parc wants to get ’em while they’re young.

Le Parc’s light installations are crowd-pleasing too, in a different way. Composed between the ‘60s and ‘90s and updated throughout the artist’s career, they alter the perception of space, depth, and time, creating moving volumes that vanish (literally) in a flash. And in the era of the camera phone they take on new meaning, presenting themselves in the captured image not as you might have remembered, but more like a ghost in a mirror.

Not far from “Jeu Enquête,” a room of hanging punching bags of the kind you’d find in a bouncy castle (each painted with a different uniformed officer), is “Lumière Verticale Visualisée,” in which vertical mirrors hang in place of the punching bags. As you walk through this mirrored maze the surfaces reflect strobe lights in all directions. It’s a journey—not quite the same as punching out a police officer in the next room, but it shakes you up before spitting you out the other end. And that, essentially, is what this art game is all about.