50 years on from its initial release, the half-forgotten short feature Maken Liner 0011 Henshin Seyo!! – directed by industry stalwart Takeshi Tamiya – might be showing its age. At the same time it has become an unexpected joy. While its animation is limited and its narrative aimed at children, its pace, design, and soundtrack represent something that shifts well beyond charming or inventive and into the realms of bug-eyed insanity. For anime enthusiasts interested in the history of the form it is a decent 50-minute example. For anyone on the lookout for the next cult artefact with which to impress their friends, do I have the anime for you.

In a future Tokyo, the scientist Dr Hayashi is ridiculed for his claims that aliens are preparing to invade the Earth. When he is targeted by those same aliens, Hayashi transforms his young son’s four pet dogs into powerful shape-shifting cyborgs. With the aid of his pets, who can now transform into the spacecraft Maken Liner, young Tsutomo must venture into the bowels of Mt Fuji to repel the alien menace.

Maken Liner was originally produced to accompany the live-action movie Kamen Rider vs Ambassador Hell in cinemas, and it benefits enormously from being made for the big screen. It is presented in the extra-wide Cinemascope film format, still a comparative rarity among animated films, and despite a simple art style and a lack of detail gains a great sense of scale and scope. There is a strong influence of Osamu Tezuka’s Astroboy in the film’s aesthetic and design. The human characters may look scrappier, but the influence shines through in scenes of high-technology cities, robots, aliens, and vehicles. There is a crispness to the technical designs and a wealth of imagination behind the increasingly alien settings. Most striking is the colour: each successive alien, monster, and giant robot in the film is expressed in vivid, bold hues.

The invading aliens are fantastic, representing a wide variety of insectoid forms with tentacles, claws, exposed brains, and shimmering patterns. It all feels just slightly too horrific for its target audience, as does the fact that they bleed out and dissolve when shot by Tsutomo and his cyborg companions. The film’s climax is also unexpectedly effective, with a countdown to disaster actually represented by a real-time countdown in the corner of the screen.

It is ultimately all so daft as to be enormously fun. The limited animation, clean design work, and surreal story will remind modern viewers of Adult Swim comedy cartoons, while younger audiences will likely just enjoy the action and the humour. At 50 minutes in length the film does not outstay its welcome, instead providing an immediate wholesome and delightful slice of children’s entertainment.