California, 2049. The replicant blade runner K (Ryan Gosling) makes a disturbing discovery at the scene of his latest mission – one that could have earth-shattering consequences for the future.

There is a common wisdom that there are some films to which you should never make a sequel. No one needs Casablanca 2 (although we did get two TV series), or Citizen Kane: The Next Chapter. Steven Spielberg personally nixed the possibility of a second E.T. I think if you jumped back a few years you would be hard-pressed to find many fans of Ridley Scott’s 1982 masterpiece Blade Runner that were particularly keen to see another director handle a follow-up.

Yet here we are, weeks after the release of Denis Villeneuve’s Blade Runner 2049. It seems a surreal time. It feels odd that the film actually exists, that some film studio actually took the risk of funding such a contentious and commercially risky project, and it seems downright surreal that Villeneuve’s film is not only good but a genuinely worthy sequel to Scott’s original film. This is the kind of a sequel that hardly ever exists. It respects its predecessor. It advances the themes and the story. Most significantly it does not copy Scott’s work, but rather uses it as a springboard for a whole raft of new settings and ideas. There is a modest list of the world’s best sequels – The Godfather Part II, The Empire Strikes Back, Toy Story 2 – and I am comfortable in sitting Blade Runner 2049 alongside them.

It feels like a quite different film. The geography is much more expansive, moving out from Los Angeles and into California and Nevada. The simple act of leaving the oppressive, rainy city of Scott’s film and revealing a dusty, arid wasteland outside does an amazing thing: it takes a film and leaves behind a universe. I am not recommending that Blade Runner continue beyond this second film, but the potential is there now. The original felt like a closed, self-contained story; this feels like a doorway to an entire franchise.

While the landscape expands, the themes and content of Blade Runner grow in the same way. Ryan Gosling plays K, a replicant – a sort of biological android – tasked with hunting runaways of his own kind. As with the replicants of the 1982 film, K is a deeply emotional man – more so than any of the humans – but he lacks the capacity to sufficient express them. In his apartment lives Joi (Ana De Armas), a holographic girlfriend simulator. She appears to be self-aware, and craving a genuine relationship with K – whom she visibly loves. He cannot give her what she desires because he cannot express the emotions she seeks. That a future 30 years after Blade Runner would incorporate a second level of artificial human is a creative masterstroke. K and Joi are unable to ever properly connect, and by making her a hologram the film renders that inability in physical terms as well as emotional ones.

The film advances the original production design in logical and respectful ways. Rather than copy Vangelis’ iconic electronic score, the film turns to Hans Zimmer and Benjamin Wallfisch to generate something much harsher and more industrial. At times the music feels overwhelming, and to a large extent I think that is the point. Ridley Scott made Blade Runner as a film noir pastiche; 2049 largely abandons that pastiche in favour of something much more aggressively contemporary. The sense of nostalgia is gone.

The cast are almost universally excellent. Gosling does sensational work with a very difficult character: how do you perform a character who experiences emotions but struggles to let them show? He gives K a tense, bottled-up intensity that is fascinating and hugely effective.

Harrison Ford, who re-enters as former blade runner Rick Deckard much later in the narrative than one might expect, is in excellent form. The screenplay gives him a lot more to work with than he usually receives, and his understated acting with that material is a good reminder of what a strong and underrated actor he is. Another actor worth noting is Dave Bautista, who makes a brief but impactful appearance as a runaway replicant. Given his towering physique his career has been dominated by action-heavy roles in Guardians of the Galaxy and Spectre. He shows here just how much more potential as a dramatic actor he has: I really hope some casting directors and producers took notice.

A real highlight of the film is Sylvia Hoeks as Luv, a replicant assassin built by and working for Wallace. Like all replicants she is an odd mess of poorly expressed emotion: in this case crying each time she murders someone. She is, to me, the film’s most intriguing character.

It is not a faultless film – but what film is? A particularly languid edit stretches a two-hour masterpiece out to 163 minutes, and that additional length – adored by some viewers – does a fair bit of harm to the story’s intensity and pace. It also suffers to an extent the same issues that crippled this year’s live-action Ghost in the Shell, in that it is a film with an overwhelmingly Caucasian cast in a world flooded with Asian design and iconography. It is nowhere close to the degree on display in Ghost, but it is unfortunately present.

A somewhat bigger issue, and one largely unnoticed by critics, is the casting of Jared Leto as the blind tech billionaire Niander Wallace. Through this casting Blade Runner 2049 joins a seemingly endless list of films willing to feature disabled characters but with able-bodied performers playing them. Hollywood largely abandoned casting actors in roles not of their ethnicity decades ago (although cross-casting of people of colour does sadly continue). The industry has yet to make the same change with the disabled. A blind character deserves a blind actor, and given the paucity of roles for disabled performers in the first place every casting of the kind Blade Runner makes is just more lemon juice squirted into the cut. To make matters worse Leto is not even particularly convincing in the role: his mannered, poorly developed performance is a glaring stand-out in a film packed with generally outstanding work. He is not convincing either as his character or as a blind man.

Despite these flaws, Blade Runner 2049 is a towering achievement. It does the unthinkable: takes one of the most popular cult films of all time and actually makes a sequel worthy of its name. It strikes me as a film that will, like its predecessor, reward multiple viewings. There is just so much to appreciate and unpack.