In Cosmic Journey, the PCs learn they are the descendents of the Galactic Roadies, and they are charged with using a Scarab Ship to travel through time to recover the Celestial Guardians and their Artifacts to play one last show. In other words, they have to reunite the rock band Journey while battling their nemesis, KISS.

The game is GMless. Players take turns resolving obstacles, which are created by the other players. A player resolving an obstacle sets and ends the scene, with the other players narrating the middle. A random roll (4 or higher on a d6) determines whether the obstacle is successfully overcome, or ends on a cliffhanger that must be resolved next turn (and gives a 1 bonus to the next roll). The game makes heavy use of "Phrase Cards", pieces of paper which have a snippet from a song by Journey, to inspire the narration.