Evaluating “Eternals” requires a few disclaimers, since it feels decidedly different from most Marvel fare. The story represents such a significant potential expansion of its “cinematic universe” that it might only be fairly judged in the rear-view mirror, once there’s time to see what fruit these seeds have borne.For that reason and others, the film is certainly interesting, and it comes with the pedigree of director/co-writer Chloé Zhao, following (with Covid-related delays figured into the lapse) the Oscar-winning “Nomadland.”Yet whatever Zhao’s indie-film sensibilities, “Eternals” must both meet the action demands associated with the genre, which it ably does, while laying out a whole lot of background as it introduces these characters and what they signify. That latter task proves more awkward and ungainly, especially during the lengthy first half that explains the premise and reassembles the team, the most inclusive Marvel has presented.”Eternals” simply takes too long getting to the good stuff, and its more cerebral and adult elements — including a grand romance — could harbor less appeal among kids, a not-inconsequential demo, than most recent Marvel titles.Based on a lesser work from Marvel artist supreme Jack Kirby (who returned to the fold after creating his signature epic “New Gods” at DC), “Eternals” focuses on beings dispatched to Earth thousands of years ago to destroy horrid creatures called Deviants that threaten its inhabitants.With extraordinary powers ranging from flight and super speed to altering matter and controlling minds, they were understandably confused with gods by ancient civilizations. Hence, names like Ikaris (Richard Madden), Sersi (Gemma Chan), Thena (Angelina Jolie), and Makkari (“The Walking Dead’s” Lauren Ridloff) found their way into various mythologies, albeit with the spelling mangled.It was always a rather cheeky conceit, and the film begins in the distant past before leaping to the present, with plenty of flashbacks to places like Mesopotamia and Babylon thrown in.After relative calm for thousands of years the Deviants have reemerged, prompting the Eternals — scattered across the globe — to spring back into action, although that first requires rounding them up, and having some fun with how they’ve occupied their ageless and endless time.At its core stand lovers Ikaris and Sersi, with Chan, the “Crazy Rich Asians” co-star, really serving as the heart of the film. Sersi has moved on to a human boyfriend played by Kit Harington, adding to a “Game of Thrones” alumni squad that includes Madden and composer Ramin Djawadi.As constructed, the film spits out tons of exposition during its first third, sags during the middle, and rallies impressively during the final leg, which is filled with surprises and genuine emotion. Plus, stick around for the customary credit sequences.All that comes a little late, though, to completely validate the movie. “Eternals” ultimately contemplates humanity, and the way these extraterrestrials see its beauty and possibilities as well as its ugliness, much like Vision’s dialogue with Ultron in the first “Avengers” sequel, or the Silver Surfer in the comics. Instructed not to interfere in human affairs, their time on Earth has left its mark on them, just as they have found their way into humankind’s mythology.It’s possible to enjoy individual moments — from Chan and Madden’s interactions to Kumail Nanjiani’s character and his amusing pastimes — and still come away thinking “Eternals” overreaches as it tries to spin this lightly regarded comic into gold.Granted, the beauty of Marvel’s interlocking universe is that by playing the long game the pieces build upon each other, so that appraisal might change as the next phase comes fully into shape. “Eternals” certainly doesn’t lack for ambition, but for now, Marvel — emboldened by its success — has reached for the stars without quite getting there.Will it eventually? Hope springs eternal.”Marvel’s Eternals” premieres Nov. 5 in US theaters. It’s rated PG-13.