This independently made British fantasy-sci-fi animated feature is described by its makers as a “motion comic film” and seems to be, judging by its end credits, the work of little more than a dozen people, six of whom worked on the song that plays over the aforementioned credits. The script is painfully derivative, an unholy alchemical amalgam that features chiselled-cheeked heroes, duplicitous helpers with parti-coloured hair, purple-skinned butterfly people whose females have perfect nipple-less breasts, a sprinkling of Metropolis-like robot workers, and a generous dash of steampunk futurism strained through the sieve of Japanese anime.

The animation itself is decidedly odd, a no-less eclectic mix of animatics, limited movement and occasional close-ups featuring hyper-realistic facial movements as if executed via a CGI version of rotoscoping. It’s also almost entirely humourless, and yet given a choice between it and, say, some Hollywood comics franchise release with a squillion-dollar budget I think I’d rather watch this. At least it feels more like the future of film-making instead of the IP-obsessed past the mainstream industry keeps foisting on us.

The plot is a car crash of storylines, with flashbacks and flashforwards that make little sense, but here’s the rough idea. Soldier Tommy Hargreaves (voiced by Harry Shotta) returns home from fighting abroad during the second world war, only to find his mother (Lauren Barton) is dead and his father Charles (Peter Kingston) has gone missing. Charles is a toymaker who treasures the key of the title, and has disappeared into a realm of his own devising that can only be accessed through some sort of wispy portal. One world is populated by the butterfly people, another has butch-looking ice ballerinas, and another is where the big bad guy of the movie dwells in a “castle in the sky”.

Tommy is in search of the key and his dad, a journey that only takes a mere 70 minutes or so but feels much longer because of all the overwrought dialogue. If you had stumbled across this on the internet, you might feel charmed to watch for the full running time. Aspiring animators are encouraged to check it out just to see what the can be done with modern tech.