The New Tetris
Set the music in the options menu to "Haluci" and set the music mode to CHOOSE. Now start a one-player game and enter your name as HALUCI. then go under ONE PLAYER and type in HALUCI as your name. Do not press START to get to the OK button, you have to manually go there with the D-pad. Press A and enjoy the show.
Credit Goes To: Treble21 via IGN 64

 Intense Gameplay

Intense Gameplay Mode
Enter your name as "2fast4u" in the single-player name entry screen. Then just play as usual, and get ready to lose, hehe.
Credit Goes