A genetically deformed gorilla, wolf, and alligator walk into a major metropolitan area and destroy buildings. That was the concept of the video game in which Rampage was based upon and the movie adaptation doesn’t burden itself with over ambition in bringing it to the screen. Throw in Dwayne Johnson and lots of CG effects and what do you get? A fairly middling experience that will probably manage to thrill teenage boys whose fathers spent their quarters on the game at the arcade in the 1980s.

Davis Okoye (Johnson) is a primatologist. He’s great with animals and doesn’t really enjoy interacting with people, as the screenplay incessantly reminds us. He’s developed a particular bond with George, an albino gorilla who lives at the sanctuary where Davis works. They’re practically a comedy team as Davis has taught him tricks like flipping the bird. The duo’s future nightclub act is disrupted when a canister of debris containing genetic mutation material lands near George and causes him to grow into a destructive beast. This nasty stuff is also consumed by the aforementioned wolf and alligator.

I could go into further plot detail on the specifics, but here’s the bottom line. Rampage is all about getting that trio of monsters en route to Chicago where they can flick tanks and helicopters into buildings with ease. Davis teams up with an engineer (Naomie Harris) and an outlaw government figure (Jeffrey Dean Morgan) to not only stop the creatures, but prevent the military from overreacting to the potential carnage. And there’s Malin Ackerman and Jake Lacy as the sister/brother duo who run the evil corporation that made the stuff that turned funny George into bad George.

Unfortunately for us, there’s about an hour of filler before Rampage reaches its Windy City destination. That time is a bit of a strain. Since it’s Dwayne Johnson playing a primatologist, it will come as no shock that he’s also ex-Special Forces. We get a bit of his background (including some anti-poaching messages) and same goes for Harris’s character who used to work at the conglomerate that wreaked this havoc.

By the time we arrive at the gorilla and wolf and alligator warfare, we’re greeted with some decent set pieces in the Transformers vein. Yet that even manages to overstay its welcome and the CG, while decent, has seen stronger offerings (it’s nothing compared to the animal work in the latest Planet of the Apes pics).

This is Johnson’s second collaboration with Brad Peyton, who directed him in San Andreas. That was another so-so spectacle that was easily digestible and forgettable. The makers of and actors in Rampage do seem to know this is silly junk food and earn some points for never taking it seriously. And there’s certainly been other video game adaptations that have been way worse. We’re talking faint praise, I suppose, but Rampage can only do so much with the simple concept of “smash building, smash car, and repeat.”

**1/2 (out of four)