For a decade now, apart from its string of ill-fated Hulk duds, I have enjoyed films from Marvel Studios categorically. They know what they’re about, play equally well for thrills and laughs and present fantasy worlds with amazing authenticity.

I’m sadly conflicted about the droll “Ant-Man and the Wasp.” The problem isn’t that it feels a wee bit insignificant following the grandiose spectacles of “Black Panther” and “Avengers: Infinity War.” That’s fine. Not every entry in a comic book franchise could or should be an apocalyptic extravaganza. Shifting to an unpretentious, small-scale story is a welcome change of pace from the usual formula.

The problem is that the third movie that Marvel released this year feels much too understated to have a cutting edge as action or comedy. Either way, it’s mild stuff.

Paul Rudd plays Scott Lang, the flawed John Doe of Marvel’s superhuman cosmos. A good guy with bad luck, he stumbled out of a nice marriage and into prison for small-time burglary. He returned to civilian life with one key goal — to be a good part-time dad to his adorable daughter (lovably played by Abby Ryder Fortson). Then he accidentally found that a high-tech suit he stole enabled him to battle evil as it shrank and supersized him.

As this chapter of his story begins, he’s under house arrest for his role in the “Captain America: Civil War” fight among opposing Avengers, with no science fiction uniform to size-adjust him out of his electronic ankle monitor. Supposedly.

The costume was created by gruff, glowering physicist Hank Pym, Lang’s reluctant mentor, whom Michael Douglas plays like Tony Stark’s crotchety dad. There’s a pleasant level of comic friction between know-it-all Hank and Scott, an amiable but semi-incompetent knight in shrinking armor. Douglas, who always seems to be just short of blowing a gasket, is as funny here as he has ever been in a movie.

Unfortunately, Peyton Reed’s “Honey, I Shrunk the Performers” directing cuts the star off too quickly. While Rudd has the superpower of being affable whenever he is on-screen, much of the cast would be more effective if they had room to breathe. That’s true even for Evangeline Lilly in one of the title roles. As poker-faced Hope Van Dyne/The Wasp, Hank’s daughter and Scott’s newly shrink-wrapped colleague/potential love interest, Lilly is even more rigid than the whiz kid she plays.

The stakes here are low, centering on possession of Pym’s office building, a skyscraper shrinkable to the size of an under-seat suitcase. There isn’t a villainous evildoer at the center of things, but a cryptic newcomer named Ghost (Hannah John-Kamen), who wants technology from Pym’s lab to control her own abilities. It’s her special power to shift abruptly from place to place, with no attempt at any real continuity — as might be said for the film itself, which is edited in a style that is hardly seamless.

The wonderfully eccentric character actor Walton Goggins is shortchanged in a supporting part as an oily con artist also wanting to seize Pym’s portable research center. Michael Peña returns to his role as Scott’s prison pal turned solid citizen Luis, and Randall Park introduces Jimmy Woo, a suspicious FBI agent eternally on Scott’s case. Both demonstrate the magic of turning inconsequential lines into comic platinum.

There are “oh, by the way” spiels about the subatomic Quantum Realm, which has trapped Hope’s poor mother (Michelle Pfeiffer) for decades, leading to visits there filmed in shades of orange that weary the eye. Ants boosted to human size show up and act like teenagers which, given their limited life spans, makes a sort of sense. And there is much attention paid to rescuing, rebuilding and retaining families, a theme explored far better in the vastly more entertaining “Incredibles 2.”

The film’s foremost accomplishments come in the lightheartedly surrealist action scenes. They are repetitive; each and every one based on gags of proportion with big items becoming small and vice versa. Yet, there’s something that keeps the endlessly repeated punch lines strangely delightful. In a fight in a restaurant kitchen, for instance, we see a bad man beaned with a salt shaker that suddenly grows to the size of a telephone booth.

I won’t say that “Ant-Man and the Wasp” feels fresh and inventive all the way through, but it certainly has its moments.