80 Days is loosely based Jules Verne's classic novel 'Around the World in Eighty Days', borrowing plot points and characters from it. Instead of simply following a linear route within the bounds of the British Empire, Fogg and Passepartout can travel to a wide variety of places all over the world not even mentioned in the novel, and all events are from Passepartout's perspective.
The story also has science fiction and steampunk elements, namely the existence of the Artificers' Guild, a world-spanning group that is the driving force behind the widespread development of automata.
The game involves heavy use of the interactive fiction, a hallmark of Inkle games, which allow the player to make story-impacting choices as they play. This is woven into the other aspects of gameplay, in which the player must choose routes from place to place around the world in real time, buying and selling items and interacting with others, all to a ticking real-time clock.
80 Days was produced following the second game in the Sorcery! series, also by Inkle, as a side project separate from their flagship series. Meg Jayanth was taken on to be the lead writer for the game, with directors Jon Ingold and Joseph Humfrey. The game's alternative history world that downsized western colonialism was born after Jayanth began to rewrite the character of Aodha from the original novel to prevent her from being a stereotype as in the original novel. This led to all of India being rewritten to fit a character like her, then other countries being adjusted, then most of the world.
- 80 Days is potentially one of the largest gamebooks in existence, clocking up at 750,000 words in total.