Alita: Battle Angel (2019) slices, dices and occasionally surprises.

Knowing nothing of the original Manga on which it’s based (the closest I can claim is that I quite enjoy the 2009 animated movie “Astro Boy”, which shares a surprising amount of story with this film), “Alita: Battle Angel” still held a strong appeal thanks to the names behind and in front of the camera. That faith was well rewarded, with a kinetic, if lightweight, cyberpunk action popcorn flick.

In 2563, a catastrophic war known as “The Fall” has left the planet devastated and only Zalem remains of the great floating cities of the Earth. While scouting the junkyard metropolis of Iron City which nestles below the lofty environs of Zalem, cyberneticist Dr Dyson Ido (Christoph Walz) discovers a disembodied female cyborg with a fully intact human brain. Ido revives the cyborg and provides her with a new body, naming her Alita (Rosa Salazar) after his deceased daughter, when she has no memory of who or what she is. Soon, Alita makes friends with Hugo (Keean Johnson), a young man who dreams of moving to the wealthy sky city and discovers the competitive sport of Motorball which offers a route to a life of luxury. But Alita has a secret and sinister forces will stop at nothing to possess it.

As well as “Astro Boy”, “Alita: Battle Angel” also has quite a lot in common with the recently released “Mortal Engines”. Both provide tantalising details of a wider back story that never gets fully explored (although Alita’s odds of getting to explore that are looking decidedly better than Mortal Engines’), both tell the first part of a frustratingly incomplete story and both take place in a pseudo-realistic but not quite authentic environment, often hewing closer to “Ready Player One” territory than perhaps it should.

It flirts with the uncanny valley, in part thanks to the never explained anime eyes of Alita which aren’t shared by any other cyborgs or characters within the movie. It also has a curious tone where – the ultra-violence apart (it rides the sharp edge of its 12A rating with dismemberments aplenty) – life in the ‘under city’ never seems to be that horrible.

As you’d expect, the special effects work is terrific, especially the motion capture work used to supplement the real performers. Alita’s big eyes quickly cease to be a big distraction, in large part due to the winning performance of Rosa Salazar. The wider cast is as you’d expect, with Christoph Walz, Jennifer Connolly and Mahershala Ali on good form and clearly having fun.

Action-wise, it has all the spectacle and excitement you could want, with the motorball sequences a particular standout.

It has to be said, though, it never ever feels like a Robert Rodriguez film – Danny Trejo’s not in it for a start – and it’s clear that producer James Cameron kept the director on a fairly tight leash, which is unsurprising given this has been a passion project  for him for over a decade.

It’s not groundbreaking or particularly original – especially if you’be seen Astro Boy – but it is exciting,  undemanding sci-fi fun. It really does feel unfortunately unfinished, though: stopping at the halfway point of the story and while the sequel-teasing coda and smirking cameo from Edward Norton promises a continuation we may have to buy an awful lot of tickets to the Avatar sequels to give Cameron the money to fund it himself.