“Gnomeo & Juliet” really had the potential to shatter to pieces like a smiling, ceramic garden gnome on concrete. “Gnomeo & Juliet”

Starring Emily Blunt and James McAvoy

Directed by Kelly Asbury

Grade: C

“Gnomeo & Juliet” really had the potential to shatter to pieces like a smiling, ceramic garden gnome on concrete.

It’s the story of “Romeo and Juliet” — played out with gnomes. The movie clearly had a lot working against it — taking on a Shakespearean tragedy using lawn decorations, cramming in musical numbers and doing it all in 3-D. That’s not to say it couldn’t have been done.

Three dimensions aside, this wouldn’t be the first time animators attempted to take on the Bard in a nonconventional manner. “The Lion King” serves as a splendid example of how to make Shakespearean tragedy accessible to children, music and all. But “Gnomeo and Juliet” is no “Lion King.”

With the film taking place in a backyard, the animation was vivid and full of entertaining visual details — things like the male gnome in a thong swimsuit or wisteria waving gently from a toilet bowl planter. Unfortunately, the 3-D added a headache and took away from the spectacle. Some of the background images weren’t even in focus.

To its credit, the movie does have some adorable characters and a plot that — at least most of the time — sticks to the script. James McAvoy and Emily Blunt are completely charming, even as Dutch-looking ornamentation. Shroom, Gnomeo’s silent, loyal fungus companion, is incredibly adorable.

But with a clear attempt to water down a serious plot, the movie doesn’t hold any of the emotional gravity of a Shakespeare play — or “The Lion King” for that matter. Tybalt does get smashed, but he returns glued together for a curtain-call dance number à la “Shrek.” The total lack of tragedy might seem appealing for a kids’ flick, but almost any classic animation tale has some darker points — see: “The Fox and the Hound,” “Bambi” — and those make them memorable.

And, yes, there are hilarious and happy plots that are successful, but “Gnomeo and Juliet” lacked any of the witty sparkle it could have had. “Toy Story 3,” for example, managed to brilliantly include allusions to well-known movies, and although “Gnomeo” does have a few amusing references and adult humor, the jokes for kids fall flat. Innuendo, like when Juliet’s nurse Nanette inquires about the girth and point of Gnomeo’s hat, is well done, but the quips meant for children — like gags involving underwear humor — are forgettable.

In addition to over-use of clichéd antics, the film relied too heavily on celebrity. Hulk Hogan, Ozzy Osbourne, Dolly Parton — the cast list is a veritable who’s who of gimmicky, C-list stars. None of them are particularly given space to shine, and their inclusion seems merely for name-recognition. Celebrity for the sake celebrity is an unwelcome crutch in this film.

Finally, though the music does fit the mood — that can’t be argued — the larger question is whether it was worked in seamlessly enough to be necessary. Elton John is phenomenal and his female singing counterpart, Lady Gaga, complements well. But the story would have done well to incorporate the music in the plot so that it felt less interjectory. “Your Song,” for example, is a litmus test woven throughout the film. When it’s done well, like when Gnomeo and Juliet kiss, it adds. When done poorly, like when Paris serenades Juliet, it seems arbitrary and distracting.

Overall, the movie avoided being the shattered wreck it could have been. But considering other brilliantly crafted children’s films that have achieved greatness with similar elements, the film has more than a few cracks that make it just mediocre.