I can't believe this movie has so much attention amongst everyone from the cine-literate to geeks and none of the reviews I've seen have compared it to the 80s classic Electric Dreams, even ironically. The essential premise is similar – what happens, writer/director Jonze asks, when you fall in love with a computer?

Lonely Theodore (Phoenix) is delaying signing the divorce papers to finalise his split from wife Catherine (Mara). He's sinking into a funk of loneliness, reduced to sex chat with anonymous strangers – the latest of which turns weird when his partner asks him to describe strangling her with a dead cat.

In a very modern paradox, he works at a service where customers furnish details about loved ones and pay him to write personalised, hand-written letters from themselves. It's the first of many sly nods to the vagaries of our tech-addicted, time-poor modern world, some much deeper than others.

Theodore and his friend Amy (Adams) live in a near future LA, with way more tall buildings and a questionable sense of clothing style, and AI operating systems are the latest thing. When Theodore buys one, he meets Samantha (Johansson), the persona it adopts after a quick screen of his personality consisting of two questions.

The ever-evolving Samantha quickly becomes much more than his digital helper as she reads and files emails, keeps his calendar and spends her downtime reading and learning everything in the online world. She soon becomes his best friend and – in a scene that's a bit creepy (which might have been Jonze's intention) – his lover, a state of affairs few of his friends question.

The movie raises far more questions than it answers and doesn't seem to take a stance on our relationship to technology and how unhealthy it might be, but that's just proof Jonze wasn't interested in a manifesto as much as a story of guy who finds love where he can get it. All her seems to be saying is that it's a strange animal indeed that can fall literally in love with a machine, and we're it. And if there's an overarching theme, it seems to be that we can relate, because we instinctively understand that given the circumstances, we'd do anything for emotional connection, even if the humanity behind it is an illusion.

Not that there aren't a lot of incisive comments and observations on our love of phones, computers etc – and they range from funny and light to dark and deep. They're all there, but Jonze' apparent determination not to issue opinions hamstrings the resolution a little. There's never any judgment of Theo, but the lack of one renders things curiously free of stakes as well. The denouement of the story also kind of renders such great story and visual design to bring the technology to life a bit redundant - what happens is exactly what might have happened with a human lover.

But there's still a huge amount to enjoy. The story is a multi-layered, brilliantly conceived example of where technology will take us, found in everything from small asides to critical parts of the plot. And the world Jonze and his production designer has built is amazing – just familiar enough to feel like we're nearly there but just foreign enough to seem like we still have a little while to go to reach it.

Phoenix couldn't do a bad role on screen if he tried, but I didn't find it his best performance. He overdoes the tics a little, pushing his glasses back up his nose so many times in the first third I wanted to yell at him to go and get them adjusted.

And if there had been a deep psychological point to where it all ended up, it's hard to say if it would have made it a better movie. We've all seen too many films ruined by shoving the director's opinions down our throats, so maybe this is the best possible film it could be.