To unlock a comet you have to beat each level under a specific time limit.

When you get pushed through the floor by a moving object such as the swing with bears on it on Make A Star 4, The King will warp you to another area of the level for your safety and give a short speech about the Royal Warp.

Set your PS2's date to just before midnight on December 31. After midnight passes, you will receive a message from the King of All Cosmos.

After completing the moon, do the stage again and make the moon into stardust. This gives you a movie of the little boy saying how rich people are different.

When you collect at least one of every object in the game, thus completing the Collection, the King of All Cosmos will give his praise as well as more balloons to carry the Prince on the Collection Menu.

After beating your friend in Space Mushroom, press triangle while the King Of All Cosmos is talking, to drop washpans on their head.

When you start a stage, the King will say "sending things to earth......" when he does that, open the disc tray and do not close it (or close it without the disc) and you will hear more things the king is sending to earth. They are pretty funny. When you are finished, just close the tray/ put in the game disc.

Clearing the various missions will unlock new songs in the game's Sound Test (found in the Vacation Memorial). You will also be able to select the songs for play during any mission you choose.

Eternal Mode (play without a time limit) is unlockable for all 16 normal stages. To earn a given stage's Eternal mode, score at least an 80 as your second score at the end of the stage.

To access Eternal once you've earned it, talk to the animal, make your selection, and choose the top choice when given a choice.

To exit the Eternal stage and save all items/cousins/presents collected, pause and press Square, and choose the left choice.

Make it to the end of the credits in the 2d version of Me & My Katamari.

By collecting 100% of the 2,434 objects in the game, your island's name board changes from wood to a strobe light name board which has many colors.

After completing the final "Crown" level at the Prince island, the King will speak and suddenly everything gets changed into sprites. The game title in 8-bit graphics will appear and players are treated to a short level of 2D Katamari Damacy with the game credits rolling at the same time. Press X to jump and use the D-pad to move in this mode.