A colorful but melancholy whimsy burns at the heart of "Finding Neverland," and it is perfectly personified by Johnny Depp in another irreproachable, unconventional performance as playwright J.M. Barrie, creator of "Peter Pan."

In every scene, Depp gives the subtle but unmistakable impression of a man who, given his druthers, would chose to live in his imagination rather than in the real world. It's not that he's leading a miserable life -- although his theatrical career and his marriage have both hit a rough patch. It's just that the Barrie of this fantasy-tinged biopic has misplaced his sense of wonder until, battling writer's block during a day in the park, he meets the Sylvia Llewelyn Davies family, a pretty widow (Kate Winslet) and her four young sons who inspire his platonic adoration, his inner child and his legendary departure from stiff theatrical convention.

Although the story, adapted from a play by Allan Knee, feels indulgent and oversimplified at times -- especially when it comes to the many fanciful (and wonderfully staged) illustrations of Barrie's "Peter Pan" plot ideas that spring from playing with the Davies boys -- "Neverland" makes up for any shortcomings with intricate, intimate performances from its exceptional cast.

Depp strikes a flawless balance of gravity and recaptured adolescence (not to mention a spot-on Scottish brogue). Winslet mixes warmth and motherly steadfastness with uncommonly compelling results. Radha Mitchell ("Man on Fire," "Phone Booth") finds both pain and pride as Barrie's emotionally forsaken wife and Julie Christie is resolute in her disapproval as Sylvia's society-minded mother.

But the picture's revelation is 11-year-old Freddie Highmore ("Two Brothers"). This little boy is nothing short of remarkable in his complex-beyond-his-years turn as Peter Davies, whom Barrie is devoted to shaking free of the childhood-choking solemnity that has gripped the boy since his father's death. It's Barrie's hope of helping Peter regain his innocence that inspires his play's hero -- the polar-opposite, forever-young character who shares the kid's name -- and the talented Highmore plays beautifully both the vulnerable childhood hope of joy still hidden in Peter's heart and the protective shell he's built around himself through achingly premature pragmatism.

Director Marc Forster ("Monster's Ball") mixes well the film's elements of light humor (oh, the disbelief in the eyes of the actors who first read the outlandish "Peter Pan" script!) and unspoken Edwardian-era emotion -- a convention that Barrie hasn't quite the courage to shun as he'd like to.

But Forster is a little clumsier and dismissive with shadows that hang over Barrie's legacy. Big life issues (like Barrie's crumbling marriage and Sylvia's terminal illness) are resolved in ways more convenient to the narrative than congruent with reality, and persistent rumors about what motivated his interest in the young Davies boys are summarily dismissed with the line, "No one will believe such nonsense."

What matters most though is that "Finding Neverland" does indeed capture with much delight the spirit that inspired "Peter Pan." But then, who could expect anything less with the singular and distinctive Johnny Depp to embody that spirit heart and soul?