In a Message Zone post, writer Jamie J provided some background information on the Ristar universe, including some facts about the comets. He wrote that the stars were "a neighbouring society of tough rock-people, they used to represent a force of destruction across the universe, coming to blows with the stars on several occasions. Once bullies of the solar system, Greedy's invasion forced them to embrace unity and instead work with the stars to fight the evil army. Post-war, they co-exist peacefully with the stars, their ways changed forever. Not in the game, btw."
- One comet is seen making a sex tape with a star during their only appearance, as Ristar and Siestar smash through their apartment.