One of the core characteristics of passion projects is that they take time to get made. A filmmaker, a musician, an entrepreneur (whoever has the concept) focuses on a more sure-fire job and picks away at their dream gig whenever they can. This approach has led to some stunning film work: Steven Spielberg’s Schindler’s List and Francis Ford Coppola’s Apocalypse Now are often-cited examples. But sometimes many years of tinkering with an idea only ruins it, the original nugget of the idea chipped away by script revisions or developments in a filmmaker’s style.

In the case of Duncan Jones (Moon, Warcraft), the filmmaker has talked about making his latest release, Mute, for years. At one time, it was going to be the immediate follow-up to Moon, Jones’ sleeper hit of a debut. Instead, Jones went on to make a studio vehicle for Jake Gyllenhaal (2011’s Source Code) and 2016’s Warcraft, the biggest and most expensive film for Jones thus far. The latter was loathed by critics, received surprisingly warmly by fans of the video game that inspired it, and yet it ended up with the kind of middling financial performance that puts any sequels in limbo.

After the alleged “minefield” of Warcraft, it made sense that Jones would return to the sci-fi world he invented, for a creative palate-cleanser. After all, the gritty near-future glimpsed in Moon was ripe for exploration: all we knew is that humanity had unlocked a clean, plentiful energy source on the Moon, and that some less-than-savoury methods were being used to harvest it.

Sadly, despite the potential, what Jones delivers with Mute is a classic example of a passion project that should have stayed on the page. The film is admirably small-scale, when a lot of futuristic science fiction aims to make big statements about humanity. But taking a narrow, Black Mirror approach to the story can’t save it from an emotionally distant main character or a repetitive, fractured plot. At times, you can almost feel Jones waffling over what to include in his story: more of Alexander Skarsgård gazing listlessly at reused sets from Blade Runner 2049, or more of Paul Rudd’s obnoxious mustache.

The story revolves around the titular mute bartender named Leo (Skarsgård) who works with his girlfriend Naadirah (Seyneb Saleh) at a club in Berlin in the 2050s. Leo’s condition dates back to a boating accident when he was a child, but he won’t get it corrected due to his Amish background. When Naadirah goes missing one night, he embarks on a journey through the city’s underbelly, running into a series of lowlifes who all seem to have some connection to Naadirah’s murky past.

A silent central character doesn’t have to be a handicap for a film – look no further than Oscar frontrunner The Shape of Water – so the problem with Leo isn’t that he can’t speak, it’s that he’s basically an empty shell. It’s hard to care about a guy who doesn’t bother to communicate with sign language, who flies into a blind rage over petty insults, and whose main interest seems to be carving things out of wood. There’s probably an interesting loner character waiting to be developed here, but Jones doesn’t crack it.

As for the other characters, far too much time is spent with two former army surgeons played by Paul Rudd and Justin Theroux. At points, it begins to feel like the movie is actually about Cactus Bill (Rudd) and Duck (Theroux), especially as Cactus wrestles with his suspicions that Duck is sexually attracted to his underage patients. What’s even more confusing is how Cactus violently confronts Duck over this in a later scene, only to go out drinking with him minutes later. These incongruities are some of the most obvious indications of how different drafts of the script got mushed together with little regard for how it all plays as a single narrative.

After Leo plods around Berlin retracing Naadirah’s steps, eventually we get to a denouement where Cactus and Duck’s real motivations and backstories are revealed. But the revelation is less of a twist and more of a “So what…?” Mute even robs us of a big showdown scene between Leo and any of the bad guys, despite a build-up based on sequences of Leo (bizarrely) gulping down huge mugs of water and wielding an ornate bed post he’s crafted. It’s these moments that make the film almost too silly to take seriously at all.

The only viable recommendation to see Mute would be targeted at super-fans of Moon, who will surely want to know if the new film offers any resolution to the Sam Bell arc. Without spoiling anything, I’ll note that Jones does deliver on this front, but the film that surrounds these tidbits is so uninspiring that it would have been better to see a ten-minute short that focuses purely on the Sam Bell material.

It’s a shame that two of the more promising original works of sci-fi to hit Netflix in the past month (The Cloverfield Paradox being the other) stumbled so hard. It’s become trendy lately to describe certain movies as being “dumped” on Netflix, but the phenomenon isn’t unique to the streaming world – rewind a few years, and you could imagine Mute being shunted to a January theatrical release instead. Fans of Duncan Jones can only hope that with Mute off his mind, maybe the filmmaker can move on to something truly fresh, and finally produce the work that Moon proved he’s capable of.

Mute gets two stars out of four.

Stray thoughts

• The film wastes a perfectly good cameo from Dominic Monaghan on a throwaway scene with disturbing robot sex.
• We’re led to believe that Noel Clarke and Robert Kazinsky’s underworld characters will have some effect on the story, but they’re largely forgotten.
• The only disappointment with this movie not getting a Blu-ray release is that we’ll miss the chance to see any deleted scenes of Sam Rockwell as Sam Bell.