Paul Rudd as Scott Lang/Ant-Man in a scene from Marvel's "Ant-Man." The film releases in the U.S. on July 17, 2015. (Zade Rosenthal/Disney/Marvel via AP)

How should I put this? “Ant-Man” is as diminutive a Marvel movie as you might guess from its title.

Unlike our titular hero, who packs a wallop despite his pint-size dimensions, this movie is surprisingly punchless.

“Ant-Man” just can’t measure up to the behemoths of the Marvel universe, such as “Iron Man,” “Captain America,” “Thor,” “Hulk,” and others.

“Ant-Man” may have been an original Avenger, but not many of us know his back-story. An aging scientist, Hank Pym played by Michael Douglas, has developed an ant suit that can shrink its wearer to the size of an ant with the push of a button. And as he shrinks in size, he increases in strength. This good scientist, the original Ant-Man, hides the technology for decades for fear it will be weaponized.

Unfortunately, his protege/successor eventually does just that.

At first blush, Rudd would seem to be an inspired choice to play Ant-Man, a.k.a. Scott Lang. Rudd has always taken a somewhat coy approach to his film roles &#8212 he often seems to be winking behind whatever mask he’s wearing.

Having to put on an ant’s mask seems tailor-made for Rudd’s skills. After all, his character is fully aware of how ridiculous his get-up is, and Rudd carries ridiculous with aplomb.

But Rudd ends up being too constrained by the script to cut loose &#8212 even though he had a hand in the screenplay.

Marvel’s other movie from last summer, “Guardians of the Galaxy,” proved that a superhero comedy can work and, given its goofy premise and the sly wit of Paul Rudd, “Ant-Man” should have been even more fun.

Why not a smart, superhero version of, say, “The Incredible Shrinking Man” or even “Honey, I Shrunk the Kids,” with Rudd wise-cracking as he encounters giant versions of everyday items along with the bad guys? If a movie called “Ant-Man” can’t be fun, what’s the point?

There’s something so ponderous about the proceedings that the film’s few flashes of wit, most of them involving Thomas the Tank Engine, barely register.

Then there’s the lumbering parallel father-daughter theme, for instance, that drags on throughout the narrative.

“This is your chance to earn that look in your daughter’s eyes, to become the hero that she already thinks you are. It’s not about saving our world, it’s about saving theirs,” Douglas’ character Dr. Hank Pym says in the film.

Hey, lighten up a bit, Pym! Did you forget the movie is called “Ant-Man?”

And much of the humor is equally leaden with punchlines so telegraphed I swear I could hear the audience muttering them moments before the actors did.

Now none of this would matter if the special effects were wow-mazing. This summer’s “Jurassic World” proves that cardboard characters, lame dialogue, and a silly plot can’t stop a movie with incredible CGI work. But the special effects of “Ant-Man” are anything but special.

Whether the tiny hero is running away from rushing bath water, dodging stomping feet on a dance floor, or riding on the back of a flying ant, the film’s CGI seems almost retro in its relatively crude presentation. The 3-D version does nothing to make it feel any more real.

“Ant-Man” was expected to become a three-movie franchise, but if this first iteration is any indication, Marvel needs to shrink its ambitions down to size &#8212 ant-size. As a supporting character in the-gangs-all-here mentality of the Avengers films, “Ant-Man” would be a fine addition. But he’s just too small to carry a movie on his own, I don’t care how much he’s increased his strength.