A considerable improvement over the frenetic, warmed-over "Shark Tale" but falling short of that "Shrek" magic, "Madagascar" certainly starts off on the right foot, or is that hoof?

When a pampered zebra at New York's Central Park Zoo gets a serious case of wanderlust, his sheltered buddies come to the rescue, only to find themselves crated and being shipped off to Africa.

But around the time the mini-menagerie is lost at sea, the story follows suit, never to regain its bearings.

It's frustrating to see this wonderful-looking, laugh-out-loud funny survival tale fall short of its potential, but that disappointment probably won't rattle the cages of its young target demo, who'll likely go mad for "Madagascar's" eye-catching visuals, rewarding it with mighty though not "Shrek"-green numbers.

Paying affectionate tribute to the style and sensibilities of Looney Tunes legends Chuck Jones and Tex Avery, the picture, written and directed by Eric Darnell ("Antz") and Tom McGrath ("The Ren & Stimpy Show"), kicks off in high comic gear, finding Marty the Zebra (voiced by Chris Rock) strutting his way through a fantasy number to the tune of "Born Free." Allusions ranging from "American Beauty" to "Cast Away" to "Frankenstein" also figure into the schematics.

While Alex the Lion (Ben Stiller), the zoo's star attraction, enjoys living the catered-to life -- as do Melman, a hypochondriacal giraffe (an ideally cast David Schwimmer) and Gloria, a no-nonsense hippo (Jada Pinkett Smith) -- Marty's feeling like he's missing the bigger picture.

When he goes AWOL in the middle of the night, Alex, Melman (walking in Kleenex boxes so he doesn't have to make contact with those germ-laden mean streets) and Gloria form a search party and ultimately track him down in Grand Central Station. But before they can catch the train back to the zoo, they're captured, boxed up and Africa-bound.

Meanwhile, above the cargo hold, an on-the-lam quartet of slap-happy penguins have commandeered the ship with the intention of heading for Antarctica. But in the ensuing melee, Alex, Marty, Melman and Gloria get thrown overboard, washing up on the shores of exotic Madagascar.

Presided over by a self-important ring-tailed lemur who answers to King Julien the 13th (voiced by Sacha Baron Cohen aka Ali G, channeling Robin Williams), the island brings out the more primal of Alex's animal instincts, much to the concern of Marty, who's beginning to look a lot like his next meal ticket.

It's around this point that "Madagascar" runs out of gas. While motivations and situations were clear-cut and energetically rendered back in the urban jungle, the script, also penned by Mark Burton and Billy Frolick, falls apart in the real jungle, especially in its attempt to deal with those darker impulses.

Up until then, the picture was looking like a keeper. Technically, the folks at PDI/DreamWorks continue to outdo themselves, and the latest level of computer animation literally jumps off the screen with an eye-popping, impossibly bright clarity.

That's especially true of the photo-realistic New York sequences. With apologies to Woody Allen, Manhattan has never looked so inviting.

The voice work, also provided by Cedric the Entertainer and Andy Richter, is uniformly solid, though Pinkett Smith's underdeveloped hippo character doesn't give her all that much to work with, unlike those scene-swiping goodfella penguins.