George Orwell’s Animal Farm is not a sacred text. There’s no rule that says it can’t be changed in adaptation, especially if, say, you wanted to add some historical perspective from the world that came to exist after the book was published in 1945. But this unforgivably sugary animation from screenwriter Nicholas Stoller and director Andy Serkis, as well as having a pretty cheapo digital look, betrays Orwell by outrageously blandifying and defanging its classic allegory of Stalinism and failed revolution with a dumb happy ending in the Disney style.

The pivotal moment when the pigs and the humans look the same happens not at the end, but around the one-hour stage into a 94-minute film, signalling that a new third act is in the offing. I was initially intrigued, wondering if there would be some ingenious finale in which a wall on the farm is knocked down. But no. The evil pig Napoleon (voiced by Seth Rogen with many a yuk-yuk-yuk) has eliminated his rival Snowball (Laverne Cox), then gobbles up corrupt human money from a newly invented agribusiness corporate character from the human world called Pilkington (Glenn Close) and takes to addressing his followers with the aid of a Big Brother-style giant screen.

Napoleon eventually gets his riotous panto-baddie comeuppance from a game bunch of young animal rebels, the farm goes up in flames and the insurgents, gathered in safety on the banks of some big stretch of water that hadn’t been obvious before, solemnly ponder what they did wrong, and avow that they shouldn’t have put their unthinking trust in a leader like Napoleon … “or even Snowball for that matter”. (So apparently something was wrong with Snowball too, but it isn’t clear what. There’s no hint of Trotskyism here.) What is the point of making a new version of Animal Farm if you are going to subtract the rage, the satire, the passion and the meaning?

• Animal Farm is in UK and Irish cinemas from 17 July, and in Australian cinemas from 16 July