This ingeniously small-scale sci-fi adventure of a tiny, shiny alien ball-being with strange powers and a taste for electricity, crisps and custard, was released the same year as Star Wars, and foreshadows E.T., but was made for just a fraction of the cost of either. It was produced for The Children’s Film Foundation, makers of intelligent, fun films for British kids, from the 1950s to the 1980s.