The New Tetris
At the Audio Options screen, set the song to "Haluci" and the music mode to "Choose." Now enter the name HALUCI to enable a kaleidoscope. Note: You have to reset the system to disable this mode.
Enter 2FAST4U as a name in Single Player. Your blocks will fall faster.
CPU Turbo Mode:
Enter AI2EZ4U? as a name in Single Player. This will make the computer's blocks fall faster.
Thanks to Revolution reader Sufyan!