The first part of a time-hopping South Korean sci-fi opus which draws on many familiar elements but is more than equal to the sum of its parts. There are extended CGI-driven alien battles involving spaceships and cities being destroyed which could easily be from the latest Marvel blockbuster. These scenes are interspersed with a period-set, wuxia-tinged costume adventure with high-flying sorcerers, knockabout comedy and martial arts sequences resembling A Chinese Ghost Story and the comedy of Stephen Chow. The time travel stuff, of course, conjures up Back to the Future – but the real glue that binds together this crazily inventive, nutty film is its contemporary coming-of-age story in which a young orphaned girl, Ean (Choi Yu-ri) – rescued from a battle with aliens in the 14th century – is desperate to understand her origins. Her foster dad is actually a shape-shifting robot in human form – yes, you read that correctly – who takes on multiple characters, all played by Kim Woo-bin who is excellent in the split-personality role. He’s a bit like a benevolent Terminator, sent from his home planet to capture aliens who have been possessing the bodies of human beings. The key to their inter-dimensional power is a luminous blue shovel, called the ‘Devine blade’, which crosses the space-time continuum and becomes a highly coveted object in both modern day Korea and the final years of the Goryeo Dynasty. The film’s contrasting, bifurcated storyline is reminiscent of Highlander, and huge credit should go to writer-director Choi Dong-hoon – plus the film’s editor – for making all the disparate parts work seamlessly together. The tone remains consistent throughout, lodged somewhere between a contemporary action fantasy and the sort of fun, zany adventures that Hollywood used to make in the 1980s. At over two and a half hours, it feels weighty, but never baggy. The cliffhanger ending is annoying, but its exciting to know there is more on the way.

Alienoid is released on digital, Blu-ray and DVD in North America on 6 December 2022 courtesy of Well Go USA.