This is one of the most accurate adaptations of the Jules Verne tale ever made. Even though the characters are humanoid animals, adds new characters, adds a balloon ride for the part of the trip, and makes a few changes (names and minor plot changes to account for the villains' schemes), for the most part the series adapts fully the major and minor plot points of the novel.
In Spain, this show's country of origin, there is a slang idiom made from this this show: "¡Tienes más peligro que Willy Fog con el abono transporte!" ("You're more dangerous than Willy Fog with a public transport pass!")
The purpose of the character, Transfer, is not only to provide a serious antagonist for the series' protagonists, but he also allows Phileas Fogg's more morally questionable actions in the original novel to happen to move the story along in ways that keep Fog in this series the unblemished hero. For instance, whereas Fogg in the book is forced to steal an elephant for an overland trek across India, the series has Fog accepting that the elephant's owner's refusal is final, only for Transfer to mug the elephant owner and impersonate him to arrange Fog and company to have that needed elephant on their trip under false pretenses for his own purposes.
While the series never achieved popularity in the United States, the English version found fame when it was broadcast on Children's BBC in the United Kingdom. The show's theme song was so popular that when Andy Crane, presenter of Children's BBC, offered viewers a Willy Fog Song Sheet printed with the lyrics, demand was overwhelming.
The original novel has the Princess change into a European dress; most adaptations have her keep her Indian dress to emphasize her Oriental character. The series reaches a compromise between the two by having the Princess wear a dark funeral sari for part of the show and a brighter-colored sari for the remainder.