★★★½

PG, 102 minutes, opens December 26 

Directors: Don Hall and Chris Williams

Stars: Ryan Potter, Scott Adsit, T. J. Miller, Daniel Henney, Jamie Chung, Damon Wayans jnr

A giddily energetic and thoroughly entertaining children's digital-animation movie, Big Hero 6 manages to make scientific research, hugs and universal healthcare attractive.

Sourced from an obscure Marvel comic book, produced by Disney's computer animators and overseen by Pixar's John Lasseter (Toy Story), the film is a carefully crafted counterpoint to the non-stop lunacy of The Lego Movie.

If the key features are unlikely, so is the setting. San Fransokyo brings Japanese tech, not to mention anime design, to the American city with a hybrid world that is a high-tech but reassuring home to 14-year-old Hiro (Ryan Potter). He has already finished high school and now spends his nights hustling illegal robot-fighting meets, where his canny creations disassemble the opposition.

Introduced to the university lab where his older brother Tadashi (Daniel Henney) works, Hiro is put on the path of scientific innovation and introduced to his brother's invention, Baymax (Scott Adsit), a personal nurse who expands into a puffy, non-threatening carer when activated and whose bill-free dedication may suggest an idealised version of US President Barack Obama's Affordable Healthcare Act.

Tragedy brings Hiro and Baymax together, and the robot's doleful manner and gentle waddle are both full of individual character and a contrast to the frenetic pace of the story (Baymax needs to do a buddy movie with TARS from Interstellar). The tale goes into overdrive when Tadashi's diverse group of friends turn their inventions into superhero powers to combat a masked villain who has stolen Hiro's breakthrough, all-purpose microbots.

"Our origin story begins," marvels one of the gang, Fred (the lively T. J. Miller), and Big Hero 6 is a meta-commentary on superhero movies, riffing on the genre's codified rituals even as they're reclaimed from overly serious adult fans and returned to young boys and girls.

The bad guy rides on an ever-changing sea of microbots, moving with an otherworldly grace, whereas the rotund Baymax is defined by tactile warmth - his prescriptive skills include reassuring embraces. Like the rest of the gang, Baymax gets updated, and seeing him made into a weapon by Hiro in the name of revenge is presented as a tragic mistake.

Given the character's oversized eyes, there is considerable pathos, but the lessons come with a buoyant energy and self-deprecating commentary that also thankfully offers a variety of female characters. Suggesting both The Incredibles and How to Train Your Dragon, Big Hero 6 puts welcome wonder back into childhood.