We'll admit, first of all, that reviewing a trailer is an inherently ridiculous idea, but in the few hours between the teaser for T2 Trainspotting (that's how the title appears therein, that's what we're calling it) dropping in the early hours of this morning, we've noticed it inspiring furious discussion online. To sum up: 'Don't they all look healthy? They must be off the smack now.'; 'It's quite feelgood really, isn't it?'; 'Ah, remember 1996? When people thought ecstasy and heroine were more or less the same thing?'; and 'That looks interesting. I'm more excited to see it now than I was two minutes ago.' We can't resist, frankly. There's loads to say.

0:01
Beautiful shot number one of many; a bar in the midst of a derelict railyard or building site, train passing by (get it?) and a red sunset haze off in the distance. This can't be Leith, because (a) there are no trains in Leith, and (b) you'd be hard-pressed to find a derelict site like that near the centre of Edinburgh these days. A darkened figure moves towards the bar…

0:02
It's Ewan 'Mark Renton' McGregor! He's here to see Jonny Lee 'Sick Boy' Miller, playing pool with himself (that's not a euphemism) in the darkened bar. 'Hello, Mark. So what you been up to… for 20 years?' Making the Star Wars prequels. Can't you tell by his haunted look? Note the time scale. The decision to directly adapt Irvine Welsh's Porno (set nine years after Trainspotting) was scrapped in favour of a new script from screenwriter John Hodge based only loosely on the original, so the twenty-year gap probably dates it to around the late 2000s. Anyway, don't they both look healthy?

0:14
'Born Slippy' by Underworld kicks in. Just in case you were in any doubt that this really is a Trainspotting sequel.

0:15
Tram cam! Renton returns to Edinburgh – possibly for the first time since ripping off the psycho Begbie and all his other mates at the end of the first film – and he's on a tram. It looks very 'present day'; look, there's Fraser's. And Princes Street. Twenty years ago when people thought of Edinburgh, they pictured tourist tat and heroin. Now it's tourist tat and The Trams. How we've gentrified, eh?

0:19
Ewan 'Spud Murphy' Bremner, looking ageless and dishevelled, also returning with a bag. He stands under the arch on Calton Road and reimagines the glorious, iconic shoplifting days of the first film, getting chased down here and bounced off a car, and you too may shed a tear for the old John Menzies… Meanwhile, McGregor updates the mantra of the first film in voiceover: 'Choose life. Choose Facebook, Twitter, Instagram, and hope that someone, somewhere cares.' Nice. Brand placement on point. Very 2016. Doesn't Spud look healthy?

0:27
'Choose looking up old flames, and wishing you'd done it all differently.' Like not having illegal sex with a minor, eh Mark? It's Diane (Kelly Macdonald), looking very official and high-powered in an office setting. 'Do you still take heroin?' she asks. Yeah, it probably wasn't that he got wrong with you, Diane. See the age-related point above. Anyway, doesn't she look… of course she does, it's Kelly Macdonald. Along with MacGregor, it's worth mentioning, probably the actor whose career took off the most out of the original ensemble cast. Not bad going for a barmaid from Newton Mearns with no formal acting training who open-auditioned for Trainspotting on the back of a leaflet she picked up.

0:33
'…and choose watching history repeat itself.' We hope not.

0:39
'Simon… I'm home.' Robert 'Begbie' Carlyle appears in Sick Boy's pub, looking like embittered, moustachioed squaddie Jim MacDonald from Coronation Street (ask your parents). He's in disguise, on account of being a baddie. Remember how Renton shot through at the end of the first film, under the very real threat of being murdered or maimed by 'Franco'? Judging by the toilet scene we glimpse, it doesn't look like that threat's been forgotten. Anyway, doesn't Begbie look… psychotic?

0:47
'Choose your future. Choose reality TV. Slut-shaming. Revenge porn. Choose a zero-hour contract, a two-hour journey to work, and choose the same for your kids, only worse. And smother the pain with an unknown dose of an unknown drug made in somebody's kitchen…' bites McGregor/Renton, while a quickly-cut montage shows us scenes of sex and drug-dealing and -taking (there's also a great shot of a night-time getaway over the foot of Victoria Street and an interesting view of a plane landing taken from above the clouds). Ken Loach it isn't, but we hope this isn't all just a checklist of millennial buzzwords. Amid the blizzard of pop-cultural reference points, the original Trainspotting told us something of the time in which it was set and the time in which it was made. This film looks fairly entertaining on the evidence so far, but hopefully at its heart, it has something to say.

1:02
'…and then – take a deep breath.' There's a lovely, pregnant moment where the music cuts, Spud falls from the roof of a high-rise, as if in a trance, then Renton appears to save him as he's about to hit the carpet (?). The dream-like ambience of much of the original is still intact, only this time it doesn't appear to be inspired by a nightmarish heroin haze. And also here is…

1:08
…an entirely unexpected change of pace. Wolf Alice's anthemic, affirmational 'Silk' kicks in, a needle hits vinyl, fast cars drive city streets, Renton and Spud look out over the hazy city from Arthur's Seat, Renton appears to be playing a gig to a crowd, seen from the point of view of a camera mounted on his microphone. A very weird scene has Renton and Sick Boy dressed in what look like knock-off Hibs and Hearts colours, as though celebrating a goal, in proper Sunshine On Leith style. It all looks very affirmational. 'You're an addict. So be addicted. Just be addicted to something else. Choose the ones you love. Choose your future. Choose life.' Renton raises his hands triumphantly in the air under Salisbury Crags, looking like a man who's just finished a charity 5k, and then the cast are in the countryside where he delivered his 'Scotland's shite' speech last time. It looks great, and very enticing, although much of it could have been shot by VisitScotland.

1:46
And then Renton gets hit by a car, and mirrors the same pose after the same incident in Trainspotting. Nostalgia hit achieved.

Much of this looks pretty good, and that's because, well, it looks pretty good. Director Danny Boyle's regular cinematographer Anthony Dod Mantle is the unsung hero of everything we've seen so far, and both his expansive shots of Edinburgh and his dimly-lit interiors are gorgeous. As for the rest? Well, we have no clue until we actually see the film, but we appear to be in for an unexpected but entirely logical volte face from the first film; where it showed the self-destruction of youth, the sense here is of finding a sense of the positive in advancing age. But we won't speculate further – the trailer's done its job in replacing our scepticism with a need to see the film in January.

T2 Trainspotting is released on 27 Jan.