There are new Christmas movies made each year, but Easter? A person would be hard-pressed to name three. The use of this underutilized holiday proves an unassuming novelty in "Hop," which, to its credit, operates on a slightly more dignified plane than director Tim Hill's previous live-action/animated forbearers (2006's "Garfield: A Tail of Two Kitties" and 2007's "Alvin and the Chipmunks"). The film's successes, though, are more due to the clever strains of the screenplay by Cinco Paul & Ken Daurio (2010's "Despicable Me") and Brian Lynch than anything else. Once the writing loses steam in the second half, things rapidly go downhill. Thank goodness, then, for Russell Brand (2010's "Get Him to the Greek"), whose acerbic, endearing voicing of the illustrious Easter Bunny is enough to keep the overstuffed plot and poorly executed action finale tolerable.

Santa Claus has got the North Pole. The Easter Bunny has Rapa Nui. As the holiday approaches and the reigning rabbit (voiced by Hugh Laurie) prepares to pass the responsibility and title down to his son, E.B. (Russell Brand), the Easter-Bunny-to-be gets cold feet and heads to Hollywood to try and make it as a drummer in a band. When the Playboy mansion turns him away (he heard they were in search of "bunnies"), E.B. hits up Fred O'Hare (James Marsden), a wayward, directionless guy in his late-twenties who hasn't yet figured out what he wants to do with his life. Currently dog-sitting for the boss of younger, career-oriented sister Samantha (Kaley Cuoco), Fred is at first horrified at the sight of a British-speaking rabbit, then befriends him after recalling a childhood memory where he spied on the Easter Bunny hiding eggs outside his house. Might Fred be a better, albeit unorthodox, choice for the job?

"Hop" begins with the Easter candy factory in full swing, every confectionary treat one could imagine going through the process of being made. In the place of elves? Bunnies and yellow chicks alike, the latter group led by the two-faced Carlos (voiced by Hank Azaria), who puts on a smiling, chirpy face but is fast growing tired of being a helper and never getting the glory of the big cheese. The alternating setup of E.B. and Fred, both having daddy issues, and their eventual chance encounter makes for an amiable first act. For a time after that, it's just as hopeful. The friendship between E.B. and Fred is amusing and sweet—never adequately explained is why no one else in the outside world bats an eye at a chatty rabbit with human-like characteristics—and the spry script excels when exploring their dynamic and E.B.'s fish-out-of-water experience.

Unfortunately, there's no follow-through. The introduction of three floppy-eared secret agents nicknamed the Pink Berets who head to Los Angeles to retrieve E.B. are an excellent, imaginative idea, but nothing is done with them. A scene where they, too, end up at the gates of the Playboy mansion is awkwardly edited and ends before there is a comedic payoff to their correspondence with Hugh Hefner. Fred's troubled relationship with his father (Gary Cole), who sees his son as a failure, is predictable and mean-spirited, while a scene where Fred selfishly upstages his kid sister Alex (Tiffany Espensen) during a school play puts him in a negative light that doesn't sit well. That he never apologizes to the visibly upset Alex is a grave oversight. Separating E.B. and Fred for most of the climax is disappointing, too, and the switch to action movie conventions drags the pacing, humor and upbeat tone way down.

Appearing in a live-action cameo, but, for the most part, solely lending his vocal talents, Russell Brand makes for an adorably caustic but good-natured E.B. A lead character, but one that is never confused for anything other than what it is—a product of CGI artists—E.B. is balanced by co-star James Marsden (2010's "Death at a Funeral"), a game player as Fred O'Hare. Marsden understands this isn't an actors' role, and yuks it up accordingly while still managing to find glimmers of truth in his struggle to please his father. Kaley Cuoco (TV's "The Big Bang Theory") has mass screen appeal and a bright future in film if she plays her cards right, but this—her first major studio role—is pretty thankless. Cuoco does good enough as Fred's sister Samantha that the viewer wishes she were in a bigger part in a less inconsequential movie. Then again, it could be worse: she could be Elizabeth Perkins (2005's "Must Love Dogs"), looking fabulous and getting maybe three lines tops as Fred's mom. As for wasting the self-deprecating Chelsea Handler in a five-minute walk-on and not giving her a single funny line, well, that's just uncalled for.

For a film that started so well in its exploration of the Easter holiday and its many traditions and myths (without, that is, touching religion with a six-foot pole), "Hop" is a cute diversion, but a wasted opportunity that stops trying after its initial sweet-talking of the audience. The plot threads are ham-fisted (why must both fathers on display be so tyrannical of their sons' futures?), the perky early momentum is fleeting, and the villain—Carlos the chick—loses all of his interest the second he stops being passive-aggressive and embraces his bad side. The soundtrack is also uneven; Poison's "Every Rose Has Its Thorn" effectively accompanies E.B.'s lonesome walk through a foreign L.A. landscape, Hole's "Celebrity Skin" is just plain odd (if catchy) for a family feature, and the prominent use of "I Want Candy," originally recorded by The Strangeloves, is overdone and lazy. Kids will be drawn to "Hop" as Easter nears, no doubt about it. It won't be an offensive waste of time for anyone, but there is no denying how much better it might have been with an extra screenplay polish and a greater willingness from director Tim Hill to think outside the box.