Not long after Disney acquired the Star Wars universe in 2012—insert evil empire joke here—the studio announced that in addition to the sequel trilogy that began with last year’s The Force Awakens, it would produce occasional “anthology” films. Though set in the same cinematic universe, these stories would not be tied directly to the characters and story arc of the new and original trilogies.

How this would work in practice was always a bit of an open question, and now, with Rogue One: A Star Wars Story, we have the beginnings of an answer. The movie, directed by Gareth Edwards (Godzilla), is largely free of the weight of myth and expectation that were borne by The Force Awakens, and this turns out to be both a good and a bad thing.

The story takes place more or less immediately before that of the first Star Wars film (and yes, by this I mean George Lucas’s 1977 original). The Empire is in the final phase of building a super-weapon capable of crushing the Rebel Alliance, even as the Alliance itself is fragile and indecisive, riven with disagreements over means and ends. One radical leader, Saw Gerrera (Forest Whitaker), has broken altogether with the other rebels and is conducting his own small-scale insurgency against the Empire on the desert moon of Jedha.

As it happens, years earlier Gerrera had rescued a young girl, Jyn Erso (Felicity Jones), when her father was captured by the Empire. Said father, Galen (Mads Mikkelsen), was a preeminent scientist whose skills were needed in order to construct the aforementioned super-weapon… Okay, fine, it’s the Death Star. As if you hadn’t figured that out already. After Jyn receives a hologram message (yep, that old saw) from her captive father, it becomes clear that the rebels’ only hope is to get their hands on the plans to the Death Star. That way, they can find any hidden weakness that might—oh, let’s just say for the sake of argument—render it vulnerable to a single, well-placed proton torpedo shot.

The bulk of Rogue One’s plot, about which I won’t say more, concerns Jyn’s efforts to verify her father’s message and acquire the Death Star plans. In this, she is assisted by a motley group consisting of Rebel intelligence agent Cassian Andor (Diego Luna); his reprogrammed Imperial enforcer droid, K-2SO (voiced by Alan Tudyk); a blind warrior-monk, Chirrut Îmwe (Donnie Yen); his shaggily martial companion, Baze Malbus (Jiang Wen); and a former Imperial pilot, Bodhi Rook (Riz Ahmed), who has defected to the rebels.

Is that an awful lot of new characters to keep track of? Yes it is, and Rogue One largely fails to establish them as distinct and three-dimensional. Jones and Luna are both intriguing in the principal roles, but their backstories are scant, and the central relationship between the two is never adequately developed, a shortcoming that becomes more significant as the film cycles toward its somewhat surprising conclusion. Among the lesser roles, Hong Kong action star Yen has some good moments as a monk trying desperately but unsuccessfully to connect with the Force, and Tudyk is customarily droll as K-2SO, the saucy droid whose rebel reprogramming has resulted in his saying “whatever comes into his circuits.”

On the Imperial side of the ledger, Ben Mendelsohn is a nefarious pleasure as Orson Krennic, the head of Imperial weapons research, alternating, depending on his audience, between preening malevolence and groveling toadiehood. A couple of old friends return as well, including Grand Moff Tarkin, who is creepily played by a CGI version of the original actor, Peter Cushing, who passed away in 1994. Whatever one’s thoughts on the tastefulness (or lack thereof) of this particular “casting” decision, it’s a gimmick that wears exceedingly thin over the multiple scenes in which Tarkin appears.

The movie’s relatively shallow characterizations are in part a byproduct of the overall pace of the script (by Chris Weitz and Tony Gilroy), which leaps from planet to planet and battle to battle with dizzying velocity: from Jedha to the rainy crags of Eadu to the beachfront Imperial HQ of Scarif. (Not to mention a trading post in deep space, the rebel base on Yavin 4, the Wobani Imperial Labor Camp…) Anyone who, like me, has ever over-planned a family vacation will be familiar with the sensation that perhaps, ultimately, there was one stop too many.

Taken individually, however, Rogue One’s stops rarely disappoint. The action sequences are vivid and kinetic, and the effects first-rate. Of particular note is an early test of the Death Star that is all the more stunning—equal parts beautiful and horrifying—for being limited to a pinpoint attack. From that designated ground zero, the ground itself ripples outward like the surface of a lake shivering in the aftermath of a powerful splash.

In many respects, the contrast between Rogue One and The Force Awakens is illustrative. Several of the protagonists of the latter film were variations on familiar themes: Rey a female Luke, Kylo Ren an adolescent Darth Vader, and Han Solo, well, an aging Han Solo. To some degree, we already knew them, or at least the tropes from which they were assembled. Moreover, they were embedded in a well-established story arc involving themes both large (the multigenerational saga of the Skywalker clan) and small (gaining knowledge of, and skill with, the Force).

Conceived primarily as a war movie rather than a Chosen One fable, Rogue One has a different, and somewhat more impersonal, story to tell. None of its protagonists are discovering hidden blood relatives or training to be Jedi masters. Because it stands on its own, the movie does not labor under the expectations of The Force Awakens, but it also lacks the mythology to lean on. (In this, it is not unlike another recent spin-off of a beloved series, Fantastic Beasts and Where to Find Them.)

With the clash between Light and Dark sides of the Force relegated to the margins, Rogue One is a story more often told in shades of gray. Jyn is initially reluctant to join “the Alliance, the rebels—whatever you’re calling yourself these days.” And who can blame her? They’re a bickery crowd that includes radicals and cowards alike, and they’re not above performing ugly acts in service of the cause. At one point Cassian confesses, “We’ve all done terrible things on behalf of the rebellion”—and indeed, we’ve witnessed one such act on his part and the preparation for another. There are compelling themes of remorse and redemption here, and it’s a shame they weren’t developed further.

Which might also be said of Rogue One more broadly. Despite many promising elements, the overall enterprise is somewhat wobbly, like a calf emerging from its mother’s shadow. These are the risks and rewards of trying something new (or new-ish): Rogue One is neither as good as a good Star Wars movie nor as bad as a bad one.