The initial concept for this game was to release all episodes in reverse order, starting with the then-recent season 7 and then all the way back to the very first episode of the classic series, An Unearthly Child (1963). However, with the game's closure in 2019, the goal wasn't reached.
In order to add new characters, the BBC, as well as the actors or their estates, had to approve them. Out of all the actors, Richard E. Grant was the only one who declined, which lead to his character not appearing in the game.