Or You Could Kiss Me, National Theatre

Theatrical conceits, much like London buses, seem these days to come in threes. Or so it is suggested by the Neil Bartlett/Handspring collaboration Or You Could Kiss Me, the third Cottesloe production this year to peer into the future, albeit only as far as 2036, whereas Mike Bartlett's Earthquakes in London leapt forward to 2525. (Completing the trifecta: Tamsin Oglesby's Really Old, Like Forty Five, set a comparatively imminent 40 years ahead.) And while Oglesby's play featured a robotic nurse, this latest opening puts some very singular puppets centre-stage, alongside a vision of infirmity that could not be either more human - or humane.

Indeed, care for the elderly is an abiding topic of this most unusual memory play, which looks back to 1971 and the start of a lifelong relationship between two South African men who meet age 19 and 20, in turn, and then leaps forward 67 years to see how it is that the self-same couple, one of whom has emphysema and is very poorly indeed, will meet their end. It's giving little away to mention that classical antecedents are invoked as a precedent for these men's approach to death. And, perhaps, to lend a rather forced gravitas to a narrative that in every other way seems deeply personal, very intensely private.

Hospitals and memory loss, puppets seen swimming and (late in the show) snogging: clearly, we're quite some way from War Horse, the visual extravaganza that Handspring is poised to take global with its Broadway run in the spring: a play about a boy and his horse that is remembered almost not at all for its text and in every way possible for its imagery and stagecraft.

And yet, just as that previous show told of a bond that even the Great War could not sever, so, too, does Or You Could Kiss Me chronicle an abiding life-long gay partnership that is given added ballast by the fact that its co-creators, Adrian Kohler and Basil Jones, are to a considerable degree its subject. We're even informed in the text that the play's events are all true, though how that can be when it comes to a future that none of its participants has yet to experience is not entirely clear.

What actually happens during the piece, which gets played out across 105 minutes or so (no interval)? Not very much, in fact, and one is aware of the altogether dazzling puppeteering taking up time that in a more conventional exercise might be devoted to charting these men's lives across a changing world of a half-century or more. Instead, we are there when they meet, party, play squash, and share a first, much-anticipated kiss, that last on a darkened road, the most intimate moments largely kept out of view of the audience as the puppeteers crowd in on one another in an onstage huddle.

It's the years Kohler and Jones have yet to reach that prove the ripest and most ingenious on stage, the so-called Old B struggling to walk or reaching for an oxygen mask with a realism guaranteed to affect anyone who has spent any time whatsoever in the presence of the elderly. Possessed of a face one feels Lucian Freud might well recognise, Old B ranks as one of the most expressive selves to reach any London stage this year, and the fact that he is made of wood and smokes only ups the wonder quotient.

The seven-strong cast includes not just Jones and Kohler and various black-clad, barefoot male assistants but also a lone black woman in a stern-faced Adjoa Andoh, who careers about the stage with or without a microphone, invoking Ovid one minute, proffering welcome-sounding meals the next. Billed as the MC, she's the self-evident outsider to events and, to that extent, as close as there is to an audience surrogate. That's just one reason why one wishes that, as directed by Neil Bartlett, Andoh might be somewhat less austere, though the absence of levity goes with the largely grievous subject matter: Handspring hasn't, in the manner available to Beckett, found the gallows humour that can accompany visions of the end.

The piece impresses as an imaginative feat made flesh (OK, wood), and as a follow-on from War Horse that takes that show's co-creators as far away as possible from the landscape of Steven Spielberg, who of course is even now turning War Horse into a film. If I was often visually awed by Or You Could Kiss Me without being moved, that may have something to do with material so rooted in those from whom it sprang that the rest of us function as something like voyeurs. But in the way that War Horse also had a goose, this one has a dog blessed with a personality, and bark, that threaten to overtake proceedings. He's cute, he wags his tail, and what more can one ask? Should the National want to capitalise on the forthcoming Christmas rush, they'd start merchandising versions of this pooch at once.

• Or You Could Kiss Me at the Cottesloe, National Theatre until 18 November