Say what you will about Brad Peyton‘s (“San Andreas“) ridiculously goofy cinematic adaptation “Rampage,” based on the 1986 arcade game of the same name, but it owns up to its inherent silliness. A big, brawny, bombastic, gleefully rambunctious big budgeted slice of pre-summer movie season ludicrousness, it has all the markings of a stupendously stupid good time at the movies — especially with Dwayne “The Rock” Johnson and a giant CG albino gorilla at the forefront of this chaotic charge. That’s what makes its fairly boring execution all the more confusing. Certainly more disappointing too. Rarely afraid to go apeshit when the moment calls for it, but never able to move far enough away from the shackles of its generic plotting to own up to its slap-happy pursuits, “Rampage” has the right attitude but the wrong execution. It doesn’t take itself too seriously, thankfully, but it only periodically lives up to its monstrously absurd intentions. Self-aware enough to avoid the pitfalls of other, lesser video game adaptations in the past, but not clever or inventive or consistently enjoyable enough to make it worth our while, “Rampage” knows how to provide one big, hairy spectacle, but it doesn’t have enough going on to go bananas for it.

Aping off of “Rise of the Planet of the Apes” before taking a hard turn into “Kong: Skull Island” and “Godzilla” (2014) territory, “Rampage” focuses on muscular primatologist Davis Okoye (Johnson), a kind-hearted hunk who is the head of the anti-poaching unit. He admits that he enjoys spending time with animals more than people because he understands animals. That’s why Davis doesn’t form many relationships with the people around him, despite all his natural charisma. That is especially true with George, an albino silverback gorilla whom only Davis can understand in full. Speaking to one another through the art of sign language, they’ve formed a special, tender bond with one another — though George has a peculiar sense of humor, one that typically involves his extended middle finger. Their oddball friendship is loving in a roughhousing sort of way, but it’s put to the test when a mysterious experiment launched from outer space lands straight into George’s jungle habitat. Infected with its green odorous chemical, George becomes a staggeringly huge, towering, aggressive beast, one that gets bigger and meaner and more agitated with each day. George becomes far removed from the sweet, misunderstood animal he once was with Davis, and the primatologist does everything he can to return his animal to his sweet ways. When the government gets involved, however, a whole lot of trouble ensues, particularly when Agent Harvey Russell (Jeffrey Dean Morgan) gets in the picture.

As it is soon revealed, George is not the only giant animal causing mayhem across the globe. One big ass wolf named Ralph, for instance, is creating trouble in the woodland area. And Ralph and George have an even bigger opponent lurking around in the waters, ready to attack. If they don’t do something, the world will soon be subjected to the unending wrath of these imposing mutated creatures. With the help of Dr. Kate Caldwell (Naomie Harris), a disgraced genetic engineer with a desire to save, however, Davis might have what it takes to stop George and his fellow gigantic creatures before they create more wreckage.

When it focuses on its monumental, city-destroying monster attacks between its oversized animals, “Rampage” can be a whole lot of fun. But that is only found during its climatic 20 minutes. The rest of its running time is sadly a bit of a slog. While The Rock brings a good heap of personality to this flick, while sharing a surprisingly touching bond with his big gorilla buddy, “Rampage” is so bogged down by its needlessly cumbersome plot that it barely gives Johnson and his CG-created friend any screentime together. If the main draw of the film is to see The Rock and his big ole’ gorilla pal take down some nasty monsters, what’s the hold-up? Unlike “Godzilla,” which effectively teased the climatic battle that ensued during its epic finale, “Rampage” isn’t particularly cunning or thoughtful. It doesn’t have anything to say. It doesn’t have any particularly meaty ideas to explore. It’s all about the clobberin’. When “Rampage” does what it sets out to do, then it can be gleefully giddy. But it takes far too long to get there, and unlike the video game it is inspired by, it doesn’t provide the goods for quite awhile. The Rock can only carry your movie for so long.

Nevertheless, “Rampage” isn’t without its delights. Jeffrey Dean Morgan is having fun like he usually does, and he relishes his southern-friend supporting role. Harris provides a nicely nuanced performance in a blockbuster that doesn’t have a clue what to do with her. And while his CG can sometimes be a little wonky, particularly towards the middle, George is a decently fleshed out character. “Rampage” knows that the emotional core of the film — should it have one — lies between this animal and man relationship, and while it’s not nearly as effective as the one shared between Ceaser and James Franco in the aforementioned “Rise of the Planet of the Apes,” you do find yourself taken in by its crude-humored charm — almost in spite of yourself, in fact.

In the right moments, Brad Peyton can stage a ceremoniously ludicrous set piece with grace and ease. It’s easy to follow the nonsense found in the last act thanks to his assured hand, and you can tell that he is having an absolute ball with its silliness. If only we could share in that enthusiasm for its tedious first two acts. Despite its big, lofty, unpretentious efforts, “Rampage” is an example of too little, too late. The fun only arrives around the 90-minute mark, and it doesn’t have enough going for it beforehand to make the whole endeavor worth recommending. It’s a shame because, when it’s on its game, it can be engaging. Unfortunately, due to its mostly lackluster and shamefully formulaic script by Ryan Engle, Carlton Cuse, Ryan J. Condal and Adam Sztykiel, “Rampage” doesn’t rouse you up as much as you’d like. If anything, it merely shakes you awake before it’s time to head back home. That’s a shame because it gets pretty close to being among the more, shall we say, tolerable video games adaptations we’ve gotten on the silver screen. In any case, you’d be better turning your money into quarters and spending your time in the lobby playing the games found there instead. At least they don’t take an hour to get to the goods. [C]