It is a free-to-play game released to coincide with the 50th Anniversary of the popular sci-fi show, with rights licensed by BBC Worldwide.

New characters and content were added to the game regularly upon them being "signed off" with both the actors and the BBC brand team.

[6] The story begins when the Eleventh Doctor and Vastra arrive in Cardiff on 16 October 1978, discovering that the Earth has been invaded by the Sontarans, who have acquired time travel and are rewriting the planet's history.

The game uses comic book style images and voice actors from the show, combined with the gameplay of Legacy, with a few enhancements.

Unlike Legacy, Infinity received a PC port via Steam, on top of a mobile version.