Independent director and producer Gary Winick goes Hollywood with 13 Going on 30, a film that does little more than remake Big by changing the gender of the protagonist. Taking the lead for the first time in a movie, Jennifer Garner gives her performance everything she has. She nails down the physical awkwardness of a 13-year-old in a suddenly grown-up body, and she gets the vocal tics just right. The screenplay itself, though not bad, fails to offer up anything original. Anyone should be able to know exactly where this film is going at all times, giving the film the unmistakable feeling that it is little more than a product. Winick keeps the audience in the film with smart casting. One sure way to spot a talented actor is to see someone transcend banal material. In Mark Ruffalo, Winick has his ace in the hole. Ruffalo does not steal his scenes, he saves them -- including a bizarre and finally winning rendition of the monster dance from Michael Jackson's "Thriller" video. Ruffalo is unable to be anything but completely believable, and he helps Garner modulate her performance so that the audience believes that everyone else in the film never questions that she is 30 even when she behaves like a 13-year-old. Judy Greer, playing the duplicitous best friend like an evil fifth cast member of Sex and the City, offers solid support. There is not a bad scene in 13 Going on 30, but simultaneously, one wishes every scene were better than it is. Had the talent of the screenwriters matched those of the performers, this film would have given Garner the same career boost that Big gave to Tom Hanks.