Katamari Forever contains 34 stages, with all but three of the stages being taken from previous titles in the series. Half of the stages take place within the mind of the King of All Cosmos, who gets knocked in the head and suffers from amnesia. The levels are black-and-white in appearance, and the objective is to roll up junk to bring color back to the stages. The other half of the stages take place in the present, where RoboKing, a robotic version of the King of All Cosmos created by the cousins, goes on a rampage and destroys all the stars in the sky.

Katamari Forever contains 34 stages, with all but three of the stages being taken from previous titles in the series. Half of the stages take place within the mind of the King of All Cosmos, who gets knocked in the head and suffers from amnesia. The levels are black-and-white in appearance, and the objective is to roll up junk to bring color back to the stages. The other half of the stages take place in the present, where RoboKing, a robotic version of the King of All Cosmos created by the cousins, goes on a rampage and destroys all the stars in the sky.