Katamari Forever is the first game in the Katamari series on PlayStation 3. It features 30 levels, which are revisited levels both from previous games and brand new ones. The King of All Cosmos has knocked his head and suffers from amnesia. An evil robot version of him called RoboKing is constructed by the cousins and the Prince must save the universe by rolling up junk once again.

As usual, the Katamari ball can only roll up things that are smaller than itself and the Prince has to make it so big that it becomes a star. The revisited levels take place inside the King's head and are in black and white. The Prince has to colour the dreams by rolling all over them.

Katamari Forever is the first game in the series to be rendered in 1080p and has a cel-shaded style. The game also features local multiplayer with online leaderboards.