Character changes
Insert Disc 1. Highlight Mr. Mackey's tie and press [Enter] to turn him into a hippie.
Insert Disc 2. Highlight Kenny's firecracker and press [Enter].
Insert Disc 3. Highlight the bull's horn and press [Enter] to transform Cartman into Ming Li.
Hidden message
Insert Disc 3. Select the Prehistoric Ice Man episode. Highlight the visitor head and press [Enter] to display a hidden message.
Insert the last disc. Select the Spooky Fish episode. Press [Down] to highlight the alien under that episode. Press [Enter] to display the message about aliens.