SUCH GREAT HEIGHTS: In Robert Zemeckis' film, 'The Walk,' Joseph Gordon-Levitt plays Philippe Petit, a death-defying Frenchman, who walked a tightrope between the Twin Towers in 1974.

When viewed in IMAX and 3D, The Walk is positively lethal. Technical wizard Robert Zemeckis (Forrest Gump) directs material treated in James Marsh's 2008 documentary Man on Wire—the true account of the French acrobat Philippe Petit's tightrope walk between the World Trade Center's twin towers. This ultimate high-wire act, performed 110 stories up, was a free, illegal show for the morning crowds.

Here the resurrected WTC looks insubstantial, sometimes like a hologram, sometimes like the lenticular image on a souvenir postcard. But the view Zemeckis creates of the potential plummet will affect many viewers with the palm-sweats, and worse. The walk sequence is engineered as exquisite torture. If it's not the actual 45 minutes in length that Petit (Joseph Gordon-Levitt) spent over the abyss, it seems that long. It's almost over. Relief sets in. That's when the nerveless Petit raises his balance pole—it weighed 55 pounds, incidentally—makes an about-face and goes for another stroll.

Whether it's Batman calculating his glide from atop a Shanghai skyscraper or Ethan Hunt's defective Spider-Man gloves slipping on the smooth glass shell of a Dubai tower, IMAX is clearly a system that is quite convincing when a terrific plunge is looming. The illusion is as harrowing as ever, and there may not be a director alive with such an instinct for how to use 3D for punch.

Yet The Walk isn't a movie that seeks our childish sense of wonder. It's a movie that talks to us like we're a pack of kids. It's powdered with sugar. Petit explains it all for you from the torch at the Statue of Liberty, with the forced, antic enthusiasm of a birthday clown. In 3D Petit is flat as a silhouette against the synthetic New York harbor background. If Marsh's documentary preserved the riddle and mystique of Petit, Zemeckis's biopic makes him a harmless mime, aiming to please.

He meets a pretty French girl (the ineffectual Charlotte Le Bon) in a Paris square while keeping in his mind his dream to conquer New York. On the way, he requires some training and paternal advice from a fatherly old maitre (Ben Kingsley). Some are snickering about Gordon-Levitt's accent Francais, but it's Kingsley, who is supposed to be Czech, who enunciates like the Little Man from Twin Peaks.

With the heist-like set-up, and the terrifying walk underway, you forgive Zemeckis' Pepe le Pew-worthy visions of French life. And, being a heist movie procedural, it brings up matters we hadn't anticipated: the weight and unruliness of the cable as it is rigged in the dark, the persistence of security guards, and even an angry, if artificial, seagull menacing Petit as he lies down (gag, choke) for a little rest in the middle of the air.

What tempers enthusiasm for The Walk, besides the cutesiness and the heavenly spun-sugar clouds, is the repeat focus on Petit's bleeding foot as if it were holy stigmata. I'm willing to consider Petit a kind of Christian fakir—he's artist in residence at St. John the Divine's Cathedral in New York City—and his apparent immunity to fear could be an example to the spiritual everywhere. But Zemeckis avoided the remoteness that's to be found (for example) in Linda and Richard Thompson's magnificently sad 1974 song "The Great Valerio." The song, based on Petit's own influence, Charles Blondin, describes the mixed emotions of watching a tightrope walker. Petit's motives should be clear even to a child—"We would all be that great hero," sings Linda—but in The Walk, there isn't the reverse angle vision of someone watching: "we falter at the sight, we stumble through the mire."

Zemeckis, who lived in the bemired New York City of the 1970s, should have understood the grit of New York back then; this script only lightly touches on the spirit of rebellion. The characters here declare themselves outlaws and anarchists, but don't do anything tough. The cops who arrest Petit in The Walk are annoyed but worshipful. The title of Marsh's documentary came from the police report—if one ever admired the seen-it-all laconicness of the NYPD, it was in hearing the way they summed up the trouble: "Man on wire." In The Walk, we certainly get the wire—just not the man.

The Walk

PG; 123 Mins.