NEW YORK — It’s the holiday legit season, and once again, Gotham’s stocking is overstuffed.Between now and January, almost a dozen new shows will vie for family auds. And except for heavyweights — like the Rockettes at Radio City Music Hall, “Dr. Seuss’ How the Grinch Stole Christmas: The Musical” or Disney’s “The Little Mermaid” (strike-permitting) — few productions are guaranteed to stand out in the crowd. That’s why most frosh entries in the holiday race tend to bank on established brands. “Wintuk” may be a world premiere at Madison Square Garden, but it carries the Cirque du Soleil imprimatur. Kid-friendly company TheaterWorksUSA may be mounting a new musical in December, but it’s adapted from popular Nickelodeon cartoon “Max and Ruby.” So what about family shows that are unknown commodities? Can they compete, or will they be crushed by a Rockette’s glittering heel or the slap of a mermaid’s tail? Several new titles are taking the risk. Take “A Dolphin Up a Tree,” an interactive tuner by Kimberly Foster in which auds shout advice to animals in sticky situations. The show is based on Foster’s book, but the title is hardly as established as, say, “Goodnight Moon,” a kid-lit classic now running as a musical at Manhattan Children’s Theater. Currently playing the DR2 theater, “Dolphin” got a jump on the competish by opening in September, when the family field was far less crowded. Meanwhile, “A Kid’s Life,” which begins previews Dec. 8 at the York, arrives in Gotham after a 32-city national tour. A tuner for the kindergarten crowd, it follows a young boy and girl whose adventures teach them about everything from environmentalism to healthy eating. The tour, which played as far afield as Los Angeles and Key West, Fla., sold roughly 65,000 tickets in 2006-07. But that won’t necessarily convince New Yorkers. “People are so conditioned that if they haven’t already heard of something, they assume it’s no good,” says Keith Markinson, the tuner’s producer-director. To build enthusiasm, Markinson, who conceived the show before hiring outside writers, is launching an aggressive Internet campaign. Bowing in December, AKidsLife.com will feature games, webisodes starring the show’s characters and an interactive element that lets users explore an online world. Full access will cost $4.99 a month, though Markinson says this will keep the site ad-free. Ideally, the website and the show will drive demand for one another. And a successful web presence, combined with the prominence of a Gotham run, could get Markinson some investing partners. So far, he has financed every aspect of “A Kid’s Life” himself, and while he would like to expand the show to longer runs at bigger venues, he can’t afford to do it alone. “It’s stressful,” he says. “You take mortgages on your house.” He keeps going, however, because he sees the tuner filling a vacancy in the family market. His own experience as a parent encouraged him to create the show in the first place. “There’s a need for good, wholesome properties,” he explains. “ ’Sesame Street’ can’t do it alone. There’s much more violent, aggressive stuff out there that kids are drawn to.” Markinson also hopes the show’s gentle tone will propel it through the competitive holiday season. “There are a lot of families in New York right now, and we wanted to offer them something other than a specific holiday show,” he says. “We put it out there, and then we work hard to get people in.” Conversely, “Wanda’s World,” a pop-rock musical aimed at kids aged 8-13, is hoping to fill the post-holiday void. The tuner — about a middle schooler with an awkwardly prominent birthmark who imagines she’s the host of a talkshow — bows Jan. 15 at the 45th Street Theater. “We’d get killed in December,” says producer Donna Trinkoff. “We just don’t have the advertising budget to compete. But January’s a little quieter. It’s a good time to get school groups in.” Still, no one’s heard of Wanda or her world, and Trinkoff concedes that world-premiering the show in New York is a risk. “But the whole point of doing it here is starting to brand your show,” she says. And in family entertainment, “brand” is always an operative word. Trinkoff says there have already been talks of turning “Wanda” into a TV series, while Markinson says he’s in negotiations for a “Kid’s Life” skein and DVD.