For two decades, Guillermo del Toro has honed a skill that few directors—especially in the mainstream studio system—have mustered: He doesn't make movies so much as build worlds. Whether it's the bustling troll marketplace in Hellboy II or a dark underground realm of child-eating monsters in Pan's Labyrinth, Del Toro's worlds exist on their own phantasmagorical plane, one where the physics and mechanics of every moving piece are thought out. It's as if the smartest kid on the planet invited you to play in the sandbox in his mind.

Having a fully formed, palpable world with an established history is particularly useful when tackling larger issues, as Del Toro did with the Spanish Civil War and the loss of innocence in Pan's and The Devil's Backbone, or with the societal roles of outcasts in Hellboy. But what does such meticulous terraforming do for a movie about gigantic robots punching the shit out of gigantic monsters while destroying whole cities? It makes it effing awesome, that's what, and Pacific Rim is like getting punched in the face with a fist full of bombastic, childish, escapist bliss.

From the get-go, Del Toro—who hasn't actually directed a film since 2008's Hellboy II—tosses his audience into a not-too-distant future and, through a quick voice-over and a montage of news clips, lays out a realistic and simplistic history for his world. The ocean floor—having apparently read a lot of Lovecraft—has cracked open a portal to another dimension, which keeps sending out snarling, neon-blooded monsters called Kaiju to wreak havoc. Humanity, in turn, has put aside its differences and formed a U.N. of ass-whompery in its army of Jaegers, 25-story-tall human-shaped machines operated by pilots who must link their minds to avoid zapping their brains while fighting.

And fight they do. Through the streets of Hong Kong and Tokyo, in the skies and under the sea. That seems like an easy recipe for awesome, but the Transformers movies showed how confusing and boring it can be to watch other kids play with their toys. Del Toro, though, orchestrates his chaos beautifully, allowing his towering beasts to be captured lumbering from afar. When the punches start flying, they land with teeth-rattling thunder. Meanwhile, we're offered a glimpse into the post-Kaiju world, where monster-alert signs hang above makeshift shelters and the black market is flooded with demand for Kaiju bones, which are ground into medicine. In other hands, these flourishes could have been springboards into hamfisted allegory, but thankfully Del Toro avoids direct allusions to Katrina and the South Asian tsunami, and he simply presents a world that has been forced to live with the looming threat of destruction.

Of course, a world under siege is only engaging if it's populated with characters you care for. It's here that Pacific Rim hits a stumbling block, offering up well-acted but generic caricatures like Rinko Kikuchi's female pilot struggling to overcome preconceptions, and Idris Elba's motivational speech-spouting commanding officer. Charlie Day provides comic relief as a Kaiju-obsessed scientist, frenetically channeling Rick Moranis' Ghostbusters nerd, while Del Toro regular Ron Perlman brings his trademark sleaze to a small roll as a black-market entrepreneur dealing in monster guts.

These characters are broadly drawn, but they're not here to touch your heart. They're here to save humanity. To do that, they must pilot 25-story robots and battle 25-story monsters. The beauty of Pacific Rim is that it's a dumb movie with brilliance lurking in the corners of its robust world, for those who want to observe it. For those who don't care, there's a robot beating the shit out of a giant fish-gorilla monster by wielding an oil tanker like a bat: further evidence that Del Toro's remains the greatest sandbox on the playground. 

Critic's Grade: A-

SEE IT: Pacific Rim is rated PG-13. It opens Friday at Cedar Hills, Eastport, Clackamas, Lloyd Center, Bridgeport, Pioneer Place, Tigard, Oak Grove, City Center, Sherwood, Sandy, Willsonville, Mill Plain.