It would likely come as a surprise to those who have studied the layers of the planet Earth that one of the deepest layers underneath the ground is packed with monsters. Lots and lots of monsters. That’s one of the key ideas behind the new sci-fi action pic Pacific Rim (which could have been easily been titled Monsters versus Robots).

The new Guillermo del Toro feature focuses on alien monsters as they wage war against the human race. When the story begins, sale the war between the monsters and man has been going on for seven years. Humans, in their attempt to survive, have created large metallic robots that can battle the monsters. Each robot is typically equipped with two “drivers” who connect with one another and the robot so that their movements are reflected in the robot’s actions. The concept is a fun one but the story unfortunately doesn’t know what to do with it.

When the characters are introduced, Raleigh Becket (Charlie Hunnam) is excited to be battling the monsters alongside his brother Yancy (Diego Klattenhoff). The two work as one team and are stoked to have an epic battle against a menacing monster on their hands. But the monsters have adapted to their opponents and soon enough, the creatures have killed Raleigh’s brother and have gained the upper hand in the war. With that, the human race settles into a complacent resistance where they build walls—about as protective as the ones in World War Z—to survive.

Raleigh works on building one such wall but is called back into military duty when it turns out that monsters have as much trouble knocking down walls as toddlers have knocking down card houses.

With intensely realistic visuals, del Toro has created a powerfully-visual world of monsters and robots here but hasn’t filled it with anyone to care about. It is amazing to witness the visual effects at work but at some point, their brilliance has faded off and the story’s bare-bones structure is revealed to be as superficial as it gets.

Of course, Becket serves as an honorable hero seeking to avenge the death of his brother. And of course, he’s teamed up with someone—a dignified soldier named Mako Mori (Rinko Kikuchi)— who has had to battle the odds and bureaucracy to have a chance to prove herself.  And of course, there’s the inevitable leader—played by Idris Elba— who must inspire his troops as the climax approaches.

“Today, we are canceling the apocalypse,” he says. Funny, I didn’t even have that on my schedule.

Charlie Day, playing a quirky scientist who wants to get inside the monster’s brain, provides the comedic highlights of the film. It’s hard not to like him and the comic vibrancy he brings to this otherwise dour production. For most of the story, he’s off doing his own thing until he inevitably realizes something that could change the course of the war.

But ultimately, the film’s annoying reliance on grand battles lessens its escapist appeal. There’s only so much one can take in this morass of metallic mayhem. There’s a visually-stunning power to the fights that was missing from the Transformers films but this story suffers from climactic fatigue. It loses its power when it sacrifices a good story for more effects, which almost always include downpours of rain. It’s as if the filmmakers wanted to challenge themselves by throwing every effect they had into the story.

Maybe the people behind this film should’ve taken a lesson from Charlie Day’s hit show It’s Always Sunny in Philadelphia. Sunshine would’ve helped here. So would’ve better characters.