For a variety of reasons, it was probably inevitable that Eternals would be the most ambitious film released to date under the Marvel Entertainment banner. While director Chloé Zhao hasn’t shown a penchant for David Lean–style epics to this point in impressive, budding career, only the faultiest of assessments would avert the conclusion that she’s the most skilled filmmaker yet to be tossed the keys to one of the fleet of revving sports cars in the comics-derived fleet of cinematic ventures. Just as significantly, the specific source material is a doozy: a quasi-philosophical saga of immortal space gods who’ve been swirling their restless fingers in cosmic affairs for untold millennia. Conceived by Jack Kirby, Marvel’s most formidable creative visionary, during his brief return to the publisher in the nineteen-seventies, the comic smacked of the literary aspirations that creeped into funny-book storytelling during that decade. An Eternals movie demands going big.

Zhao indeed goes big. Eternals spans thousands of years, introducing viewers to notions of universal order dictated by towering, cryptic figures in the process. The Eternals arrived on Earth when mankind was still shaking off prehistoric primitivism. Over the years and across the globe, the Eternals used super-powers to protect frail humans from the snarling, chomping beasties known as the Deviants. They maintained a strict policy of not interfering otherwise, which led to occasional anguish as they turned away from other vicious brutalities regularly perpetrated by the native residents of the planet.

Much as the chronological and geographic vastness of the narrative exceeds anything Marvel has previously released — and, really, most movies outside of 2001: A Space Odyssey or Cloud Atlas — it’s the allowance for moral ambiguity that most distinguishes Eternals. Zhao and her collaborators (including Patrick Burleigh, Ryan Firpo, and Kaz Firpo, who share screenwriter credit with Zhao) do their level best to unbolt the Marvel machine from the steel-floor safety of good guys versus bad guys. They introduce tricky concepts of faith and dare to suggest that someone equipped with a snappy costume and the ability to shoot power blasts from his fists might choose to walk away from a battle, no matter how inspiring the rallying speech might be. The noble intent crashes headlong into the obligation to fulfill the Marvel mandate of big, booming action sequences and narrative mirrors that catch reflections, however fleeting, of other movies — and now television series — coming down the assembly line. Eternals strains to be more, but can’t quite break free of its strictures. It’s the most familiar beats — the comic relief, the simplified romance, the idle Avengers talk — that clang discordantly.

Zhao sometimes gets lost in her own boldness, and the generously budgeted gloss wipes away too much of the visual poetry that was the most distinctive element of her name–making features. At times, her mammoth chomp results so clearly results in an unreasonable mouthful that she can practically be heard coughing up foodstuff detritus outside the frame. It is in that sense that Eternals is most faithful to Kirby’s vision. The film is flawed, and it will surely suffer in some quarters because it is the Marvel movie that is least invested in being an eager entertainment. But, damn, it strives. That’s what Kirby did, too, every time he sat behind his drawing board.