Starring Kate del Castillo and Adrian Alonso. Rated PG. Opens Friday, April 4, at the Fifth Avenue Cinemas

The next time some melancholy sentimentalist tells you that they don’t make family movies like they used to, tell them to catch Under the Same Moon. A Mexican film that earned a standing ovation when it played the Sundance Film Festival, it’s the kind of old-school boy-loves-his-mom weeper that would have impressed the studio bosses back in the golden age of MGM. Director Patricia Riggen gets a lot of new-school things right, too, including a rollicking, Latin-flavoured score that sounds like it’s blasting from an overheated radio. But the biggest asset here has to be the winning performance of Adrian Alonso as nine-year-old Carlitos. He’s simply irresistible as a bright, fun-loving kid who looks after his ailing grandmother with the grace of someone twice his age.

Alas, granny’s nagging cough signals that she won’t be around for long. When she dies in her sleep, the resourceful Carlitos risks everything to cross the border from Mexico to East L.A. Armed with little more than a backpack and an ingratiating personality, he sets out to find his mother, Rosario (Kate del Castillo), an illegal alien who has been keeping in touch with her son through tearful weekly phone calls for the past four years.

A lot of what follows is in the mould of a classic road movie. Carlitos encounters both the best and worst of humanity on a quest that’s really about self-discovery. People come and go with the alarming speed of life on the run. But when the boy latches onto a cynical illegal named Enrique (Eugenio Derbez), the luck of both travellers starts to change for the better. Much to his surprise, Enrique becomes emotionally attached to the kid. Thankfully, none of this gets overly sentimental. Riggen keeps things hopping with more than a few satirical jabs at everything from upper-class American snobbery to U.S. immigration policy. That said, it’s really the heart-wrenching possibility of a mother-and-child reunion that gives Under the Same Moon its undeniable power. Bring a Kleenex for this one; odds are you’re going to need it.