Here’s a film to remind you that while most guys of 45 have paunch-bulges on their tummy that balloon outwards as they bend forward, Dwayne Johnson gets two or three on the back of his big shaven head when he looks up. The nape of the man-mountain’s neck ripples with mini spare tyres. And he’s doing a lot of gym-built rubbernecking at the ginormous creatures crashing around overhead in this enjoyably preposterous summer actioner, based on the 80s video game of the same name. It’s directed by Brad Peyton, who was also in charge of San Andreas, Dwayne’s last movie featuring a lot of helicopters.

Dwayne feels awe, fear, anger and a certain type of embattled kinship with these mega-animals. He sort of feels their pain, as the uber-beasts roar, rear up on their hind legs and do extensive CGI-rendered damage in urban environments, their hairy pelts bristling with the futile tranquilliser darts that uncaring military personnel have blasted into them.

This is the story of one big and big-hearted guy and his poignant bro-apemance with George, the sweet-natured albino gorilla who is accidentally administered an illegal genetic supersizer drug and starts growing and growing like a sinister mix of Alien and Elsa from Born Free. Johnson plays Davis Okoye, whose casually confident masculinity is as impressive as his scientific expertise in the field of primatology at the San Diego nature reserve. Having once been a special forces hombre, tackling poachers, Davis has chosen to retrain as a zoo guy, albeit one built like a brick convenience. It is here that he teaches younger postgrads, including hot younger women whose interest in him gets politely rebuffed in the service of underlining his heterosexual family-movie leading male credentials.

But up in space, a creepy corporation is developing a genetic editing programme that will mess with the proportions and energy levels of otherwise innocuous domestic animals. Why, oh why, do these experiments need to be in space? Something to do with zero-atmosphere or zero-gravity? Or is it just so we can see a gigantic rat crashing around in a spaceship? Either way, these deplorable procedures come to grief, and canisters bristling with growth hormones explode meteorically out of the craft, plunge through the atmosphere and down into the San Diego reserve where their insidious little microparticles make their way into the nostrils of George, the lovable gorilla with whom only the day before Davis was exchanging high-spirited sign-language banter.

Soon George is growing out of control, and so are a few other animals, including a wolf and something that looks like a crocodile crossed with a warthog. The only person who can talk to George, and maybe even get his assistance in tackling the whole big-animal-chaos issue, is Davis. In the traditional creature-feature manner, he gets assistance from a bona fide scientist who was once employed by the same creepy corporation running the experiments, until she realised how irresponsible they were: this is Dr Kate Caldwell, played by Naomie Harris.

Facebook Twitter Pinterest Out of control … Dwayne Johnson, Jeffrey Dean Morgan and Naomie Harris. Photograph: Allstar/New Line Cinema

The pair of them are also given grudging help from a government agent named Russell, played by Jeffrey Dean Morgan: a good-ol’ Texan boy who is permitted a pearl-handled revolver in an open-carry holster attached to his belt. “When science shits the bed,” says Russell brusquely, “I’m the guy they call to change the sheets.” Charming. As for the evil corporation, this appears to be run by just two people, who may be married or may be creepy squabbling siblings, played by Malin Åkerman and Jake Lacy – although they could as well be played by Amy Poehler and Will Arnett, recreating their performances from Blades of Glory.

It is entertainingly over the top, although perhaps the CGI work isn’t quite out of the top drawer. Maybe if quite so much of the budget hadn’t been splurged on that rats-in-space scene at the beginning, the crashing helicopter work could have been fine tuned. As for Rampage 2, surely one of the army of screenwriters is going to wonder out loud what would happen if Dwayne Johnson himself accidentally inhaled the supersize drug. It doesn’t bear thinking about.

