VENICE – Playing an online shrink, Tilda Swinton raps for about 30 seconds at the midpoint of “The Zero Theorem” — a stiff, Scots-accented Fresh Prince breakdown performed from under a broom-like hairpiece. It doesn’t advance the story in any way, but then, nothing here does; her screen is switched off and the rap passes without comment, like a slippery fart in an elevator; the onscreen witnesses look sheepish to have heard it at all.

I lead with this otherwise irrelevant detail because it’s the one moment in the film I can imagine hapless uninitiated viewers hearing about, and latching onto as a single reason to see the ghastly whole: “Tilda Swinton raps? This movie sounds crazy! This I gotta see.” But you don’t: it’s merely a tone-deaf gag that perhaps has marginally more YouTube life in it than the surfeit of other tone-deaf gags in “The Zero Theorem,” a British-French-Romanian-produced sci-fi bauble that says ‘no’ to little, and has evidently been said ‘no’ to a lot. Terry Gilliam films are hard to get made these days even if you’re Terry Gilliam, a truth you could use to prompt a speech decrying the lack of eccentricity and risk-taking in studio-film fantasy, if not for a compelling alternative argument: Terry Gilliam films are hard to get made these days because Terry Gilliam films these days are kind of awful.

The British-adopted American arguably reached a more hopeful brink of awfulness with 2009’s “The Imaginarium of Doctor Parnassus,” a botched but genuinely reckless formal gambit that at least has compelling design work on its side. But “The Zero Theorem” represents an alarming backslide, perhaps even past Gilliam’s last film to play the Lido, 2005’s desperate “The Brothers Grimm.” A dystopian quest narrative that offers ample density without complexity, its superficial structural and symbolic parallels to “Brazil” — still, at 28 years of age, the director’s most broadly admired film — suggest even Gilliam has clocked, and tired of, his creative decline. (We’ll give the benefit of the doubt and say “parallels” when a director cribs from his own oeuvre, but first-time screenwriter Pat Rushin should arguably face harsher charges of thievery.)

Still, a strain (and I do mean strain) of disheartened self-nostalgia runs through “Theorem,” touching on more than just the bureaucratic terror of “Brazil”: its slap-headed  victim-hero Qohan Leth (played by Christoph Waltz, also shorn of eyebrows and confidence) is a feyer Euro cousin to Bruce Willis in “12 Monkeys,” for starters. Never mind that “The Zero Theorem” is essentially an obscure synonym for the already-taken “The Meaning of Life.” None of the visual and story cues prompt comparisons that flatter the new film to any degree, though, while you needn’t even view it relation to past works to wonder why it looks so appalling, with slipshod post-production and cinematographer Nicola Pecorini’s hard lighting doing little to build upon a resourcefully spent but palpably meager budget.

What’s it about? I’m inclined to say nothing at all, though proceedings are certainly busy enough, so I assume things happen between all the shouting and internet sex and singing pizza boxes. It’s every cash-strapped sci-fi director’s favorite period, The Near Future: street denizens wear neon rollerblades and what appears to be last season’s Junya Watanabe, and David Thewlis’ software company employee is still rocking a Macklemore haircut. (I peg it at November 2014.)

The Mancom Corporation is not a new gay socializing app, but a large technology company that performs some kind of Big Brother-y, data-preserving variety of Stuff — insert Miranda Priestly’s testy eyebrow-raise here — and is headed up by Matt Damon in his second-worst coiffure of 2013. Damon, otherwise known as The Management, employs reclusive computer whiz Leth to hack away at the titular theorem: a supposedly intricate process that appears to involve playing a version of Minesweeper that would have blown your mind back when the George Bush, Sr, was still President. Once cracked, I think the Theorem reveals The Meaning of Life, though I could be wrong about that, since Leth also spends years waiting for a phone call that, he believes, will also let him in on The Meaning of Life. Perhaps there are two Meanings. Perhaps Leth is simply covering his bases. Either way, you will come away feeling considerably older, if no wiser.

I’m being glib, but it’s not as if Rushin’s screenplay offers much in the way of an alternative, as it feeds us helpful lines like, “The nature of the origin of the call remains quintessentially a mystery to us.” Well, okay. Be that way, then. Gilliam’s brand has always been dependent on an element of obtuse whimsy, but at no point in “The Zero Theorem” did I feel I was playing catch-up to anything or anyone, particularly as its rather shabby utopian aspirations come into focus.

In the closest thing the story has to an emotional nub, Leth pursues twinkly French cyber-callgirl Bainsley (Melanie Thierry) through a virtual reality suit that encouragingly suggests “Holy Motors” is at least one film Gilliam has enjoyed in the last two years. (Hers is a cone-breasted catsuit straight from Madonna’s 1990 Blonde Ambition collection: “This thing is years ahead of the competition,” she says, somewhat unexpectedly revealing that, even in The Near Future, the competition will still be Paula Abdul. Who knew?)

Naturally, they fall in love with each other, even if one or the other or both is merely a construct of a figment of a byte of something: their getaway, and a projection of our potential salvation, is a digitally-constructed beach at perma-sunset, where a piano-lounge cover of Radiohead’s “Creep” plays on loop. I don’t know if changing the music is an option. I hope it is.  It’s the final proof, however, that Gilliam’s claustrophobic, maximal brand of futurism  is so rigidly stuck in 1995 — coincidentally or otherwise, the last time he made a fully satisfying film — that “The Zero Theorem” plays practically as a period piece. Tilda Rap and all.