Kaleidoscope
Go to the options screen and change the song to Haluci and the music mode to Choose.Now start a single player mode and put in HALUCI as the name, highlight OK and press A to start.
Get Fast Mode
Start a single player game and enter 2FAST4U as the name. Highlight OK and press A to start.
Turbo CPU mode
Select single player mode, enter "AI2EZ4U?" as a name, then highlight "OK" and press A. When the game begins, the CPU's blocks will fall very quickly, while your blocks will remain at normal speed.
Erase Data
To clear all the lines on your New Tetris Pak and reset all the Wonders, enter "O1DERS" as your New Name. To clear all Game Pak data, including high scores, enter "1N175R4M" as your name.