The "Godzilla" reboot perfectly illustrates the problem that has long haunted mediocre monster movies. When the big, scaly guys are on screen, it’s a fun thrill ride. But when the humans are at the center of the action, things get scary — and not in a good way.

That’s unfortunate, as this revamp of the Japanese classic has so much going for it. Director Gareth Edwards is known on the cinematic underground for the creepily effective 2010 low-budget chiller "Monsters." The cast is nothing if not eclectic: Bryan Cranston, Juliette Binoche, Ken Watanabe, Sally Hawkins, Elizabeth Olsen and a beefed-up Aaron Taylor-Johnson, the formerly lanky sorta-superhero in the "Kick-Ass" movies.

Certainly, after Roland Emmerich’s famous 1998 botch of the tale (the one with Matthew Broderick), the 2008 "Godzilla" wannabe "Cloverfield," and last year’s middling monster mash "Pacific Rim," the world is ready for the real deal. Not to mention there are all the best special effects that $160 million can buy. It’s just too bad a better script wasn’t in the budget, too.

"Godzilla" begins in 1999 Japan, where Joe Brody (Cranston), a scientist at a nuclear facility, is alarmed by a sudden upsurge in seismic activity. It turns out he has good reason to be worried: Giant prehistoric­like creatures that live at the bottom of our world have been awakened.

Part of a city is destroyed, and lots of people are killed, including Brody’s wife, though his young son survives. But Japanese officials are able to quarantine the area and put out a cover story, meaning the world is none the wiser that there are monsters in our midst.

A flash-forward to present day finds Joe a wild-eyed obsessive trying to prove the Japanese are lying while his now-adult son (Taylor-Johnson), happily married in San Francisco to a nurse (Olsen) and with a son of his own, wants him to just let it go.

‘GODZILLA’ Rated: PG-13 Opens Friday

But then a new round of seismic activity starts, and this time the Japanese can’t keep a lid on it because a couple of MUTOs (massive unidentified terrestrial organisms — basically, the old Japanese monster Mothra with a Hollywood face-lift) are on the loose.

How can mankind hope to survive? Well, according to Dr. Serizawa (Watanabe), nature always provides a balance. In this case, it’s another creature from the deep: Godzilla, MUTOs’ sworn enemy. The U.S. Army, of course, just wants to nuke ’em all, but since these things feast on radioactivity, that might not work out so well.

Honolulu, Las Vegas and San Francisco are the monsters’ ports of call, and seeing these towns digitally taken down is where "Godzilla" hits its stride. There are some genuinely tense scenes, as when two soldiers struggle to stay silent on a bridge trestle while a MUTO stalks underneath. The entire Golden Gate Bridge and Honolulu train sequences are masterfully staged, and so are the scenes where planes plunge from the sky. And, yes, Godzilla looks awesome.

As effective as these moments are, they can’t compensate for the fact that two of the film’s best assets (Cranston, Binoche) don’t have much screen time, the acting is generally wooden (Watanabe and a totally underused Hawkins, as his assistant, spend the whole time just looking pained), and that our hero, Taylor-Johnson, is a blank, bringing little to the part except an obviously successful workout routine.

On top of that, the script by Max Borenstein recycles monster-movie tropes without adding much new to them. The Japanese and American monster movies of the ’50s tapped into Atomic Era dread. Borenstein and Edwards don’t expand beyond that — a surprise, because Edwards’ "Monsters" was inventive in its sociopolitical implications, as it was set along the U.S.-Mexico border.

Here, the filmmakers often just seem to mistake confusion and cacophony for plotting.

Maybe, if there’s a sequel — which this one leaves the door open for — they could find a way to jettison the humans completely. That would be an improvement.

Cary Darling, Fort Worth (Texas) Star-Telegram

BIG G ON THE BIG SCREEN 

Highlights from the monster mashes: