Co-adapted by co-directors Chris Buck and Jennifer Lee from one of Hans Christian Andersen’s moral tales, Frozen proved Disney Animation Studios’ most commercial and critical success in some time, earning an Oscar and more money than any other animated film ever. Happy-ever-after following a cold quest and rollercoaster unraveling, this “instant classic” has not, however, been properly seen as a representative of the cultural sea change that it in fact is.

Old-school “classics” did have baddies -- Michael Cohn’s bloody 1997 Snow White: A Tale of Terror does not match the 1937 original’s nasty queen-witch or 1959 Maleficent for kiddie nightmares. Oldies did have life lessons in sadness, like the forest fire and death of Bambi’s mother; and they also had drunken, pink elephant bad trips or frightening monstrous whales and transformations of mischievous boys into donkeys.

But such films did not have major lying would-be murderous cads like Hans of the Southern Isles (voice of Santino Fonktana); they did not descend to grown-ups’ ideas of with-it teentalk like that of feisty heroine Princess Anna (voice of Kristen Bell), and they uncovered not the slightest verbal or visual whisper of bodily or sexual functions among their perfect virginal heroes and heroines.

Cartoons are no longer aimed at kids -- if indeed kids still exist -- are not, huffed a headman, “just for little girls.” Sometime following World War II, admen and studio execs fixed on the new target demographic of teen to twenties, as documented for instance in Teenage. Pushed to an ever-earlier upper-limit age, childhood is all too brief and is perverted into aping the adult world in toddler beauty queens, models and dancers. Teen mentality rules the roost and the wallet. Thus today’s hip wisecracking cartoon often cat characters and mediocre pop-music scores.

Even as child princess, Elsa (voice of Eva Bella) had the unwelcome Midas-variant curse of freezing small or enormous objects with a hand motion. Accordingly quarantined from life and people after inadvertently nearly doing in little Anna (voice of Livvy Stubenrauch), she (voice of Idina Menzel) succeeds to the throne on their parents’ deaths but later forgets herself on coming-of-age coronation day. Upset at the impetuous younger sister’s minutes-long courtship by and engagement to Hans, the now-queen loses a protective glove, freezes the kingdom Arendelle into never-ending winter, and exiles herself to a North Mountain ice palace.

Refusing to accept this situation and their long separation, Anna leaves her brief fiancé in charge and goes to rescue and thaw her sister’s heart. On the perilous quest, she is seconded by square-jawed ice-cutter Kristoff (voice of Jonathan Groff), his faithful reindeer companion Sven, and comic relief snowman Olaf (voice of Josh Gad) who dreams of basking in heat, though they also need love advice from the troll tribe who have raised orphan Kristoff.

Little more than serviceable songs take up part of the hundred-eight minutes, though to be fair few could compare with Disney’s witty, catchy, still-famous numbers of the ‘30s, ‘40s and ‘50s. But the CGI effects do improve and grow ever more impressive. And the fairy-tale ending promises not only marriage, benevolent rule, eternal sunshine and spotless minds, but adds the didactic twist that “the only fixer-upper” true love is not restricted to coming exclusively from a lover.

(Released by Walt Disney Pictures and rated “PG” for some action and mild rude humor.)