To begin with, Jupiter Ascending is pulp sci-fi of a very ancient stripe, and it is utterly proud of that fact. It tells the story of a secret space princess, set against the machinations of evil space corporations who hire burly lizardmen with bat wings as their guards; characters have names like "Titus Abrasax" and "Stinger Apini" and the protagonist gets the suitably alliterative handle "Jupiter Jones". From the look of it, one can quickly assume that sibling directors the Wachowskis, costume designer Kym Barrett, and production designer Hugh Bateup all spend months poring over magazine and paperback covers from the '40s and '50s before one sketch was drawn or one line of dialogue was written. And then the Wachowskis perhaps used those covers for their storyboards.

It's derivative as all hell, and yet it's like absolutely nothing that has come around in years: an extravagantly costly effects-driven adventure tailor-made for the narrowest slice of middle-aged genre fanboys. The only recent films to operate in anything like the same mode both tried mightily to distance themselves from all the goofy, juvenile trappings of the genre in different ways: the infamous 2012 flop John Carter by treating everything with crushing solemnity and leaden ponderousness, the 2014 smash hit Guardians of the Galaxy by coating everything in a protective layer of self-mocking irony. No such distance is afforded Jupiter Ascending, which openly loves the corny bullshit it's referencing and wants to bring it to breathtakingly gorgeous life with all of the money the Wachowskis could spirit away from a surprisingly spend-happy Warner Bros. (I have to assume it's this difference - total irony vs. total sincerity - that accounts for GotG receiving critical praise and becoming an enormous financial success, while JA has found only critical scolding and audience indifference, since they're otherwise virtually indistinguishable as exceptionally effective Star Wars knock-offs). It is a film that combines a passionate desire to remain forever 12 years old with the giddy engagement with Big Ideas that is the primary unifying characteristic of the Wachowskis' filmography; it's less the follow-up to their maddeningly under-appreciated Cloud Atlas (a collaboration with Tom Tykwer, which maybe explains the difference) than to their candy-colored pixie stix orgasm Speed Racer with more immediate gratification and a slightly more adolescent than pre-teen worldview.

The story is at once galaxy-spanning and blunt enough that you could write it on a cocktail napkin. The short version: Cinderella in space. Our hero is the aforementioned Jupiter Jones (Mila Kunis), born in the middle of the ocean while her single mother took her from Russia to the United States after the death of her English father, and now she actually does work as a maid. She's one of the cogs in the family business cleaning rich people's condos in Chicago (indulgent aside: the film makes spectacular use of Chicago's particular architecture and layout - nothing since The Dark Knight itself has been half so good in this respect), mostly stuck with the toilets for added indignation. But she is a Chosen One; the siblings of the unfathomably wealthy Abrasax family, a powerful dynasty of space industrialists, want her for their own reasons. Sister Kalique (Tuppence Middleton) and younger brother Titus (Douglas Booth) both seem to be at least kind of decent about it, but elder brother Balem (Eddie Redmayne), most powerful of the three, is extremely Bad News, with his all-black wardrobe, and his way of menacingly whispering theatrically.

He's the one who throws some terrifying skeletal beasts at her to kill her, from which she's saved by Caine Wise (Channing Tatum), a bounty hunter with canid features just pronounced enough to not make Tatum look ugly. At which point we still know nothing, until Cain's earthbound alien friend Stinger (Sean Bean) discovers that she is, improbably, space royalty. Which is still rather more the start of things than the end of them: while it's a complete canard that Jupiter Ascending has a significantly complicated plot (everything important gets repeated, at least once), it does have an awfully overstuffed one, and it can hardly set up Jupiter as the resurrection of the Abrasax materfamilas fast enough to get to its galactic soap opera and dynastic wrangling.

It's neither elegant nor sophisticated, but the rush I, for one, got from following around all the story turns hits exactly the right beats: at its best, it's like a slightly dumber iteration of Isaac Asimov's Foundation universe, at its worst, it's still got the manic "we just escape from something that wants to kill us, but there's something else that wants to kill us even more!" pacing of a trashy adventure, mixed with fairy tale melodrama: one of the two climaxes hinges on a thrilling cross-cut race to interrupt a wedding with a scheming Victorian-style villain. Throughout, the Wachowski's script, and their direction of the actors wielding sometimes unmentionable lines, strikes a tasty mixture of taking itself deadly seriously when it has to for the sake of world-building, but openly and even arrogantly owning up to how very, very silly it can all be. So when the film needs us to believe in its batshit religion of genetics - or at least believe that the characters believe it - it presents reams of crazed technobabble (only Kunis, of the main cast, gets away without having to manage any walls of impenetrable text) with unblinking seriousness and gaping fascination. But when it wants to be a gorgeously over-designed piece of nonsensical eye candy, it can happily pull back and breezily let the movie be loopy fun, and so we get things like the wonderfully choreographed aerial fight over downtown Chicago that ends the film's... first act? Second? It's got a weird number of acts. It's fast paced and zippily edited, but slows down and backs off enough that there's never a point where it's confusing, and it all takes place from dusk to twilight, beautifully captured by cinematographer John Toll.

There are some absolutely unnecessary missteps, including a brutal shift from the first finale into the second, a weird reboot that has the feel of combining a planned sequel into the first film as insurance against not getting to make another one (which turns out to have been wise), and the actors are all over the map, from Redmayne's straight-up '30s matinee serial hamming to Tatum's quiet bafflement (only Bean, out of the whole cast, gives a clear-cut, classically "good" performance). And it's not apologetic for being a gee-whiz bit of fast-paced fluff, which makes it incredibly hard to suggest that it has any business being watched by sensible people who care about depth, weight, and emotions (Exhibit B: the awkward fumbling of everything that has anything to do with the love story between Jupiter and Cain). So I get why somebody would find it intolerably trashy. But set that against the sheer enormousness of its spectacle, its passionate respect for the highest and lowest achievements of its genre, its dazzlingly overwrought visuals, its vigorous post-John Williams score by Michael Giacchino, and I just cannot convince myself that I didn't have an enormous amount of fun.