But it’s a visually beguiling small-town nostalgia trip, as well as a perfectly pleasant fish-out-of-water fable — literally, since it’s about a boy sea monster who longs to go ashore.
Yet it’s built around one original minor trope of fairy-tale nonsense: In this movie, when a sea monster like Luca , the movie still has fun with it, especially when the conceit turns into a constant threat of blowing the sea monsters’ cover.
Luca is desperate to go ashore, despite the dire warnings of his parents, the brassy Daniela , who’s like the sea-monster version of a Jonas brother, and who’s been on land for a while, living in an abandoned stone castle column as a real boy.
“Luca” is the first feature directed by Enrico Casarosa, who made the celebrated 2011 Pixar short “La Luna,” and while his images have a perky bravura , the script, by Jesse Andrews and Mike Jones, is pretty thin stuff.
And Luca’s parents, distressed at his disappearance, show up in Portorosso in their own human guise, dropping water balloons on kids to see if one of them will turn back into their son.
At last, the film arrives at the Portorosso Cup and has some fun with it, as Luca attempts to do the swimming portion of the triathlon in an ancient diver’s suit, only to learn, by the time they’re on bikes, that it has begun to rain, which will turn these sea monsters right back to their natural selves.