Power on the game and then hold the A and B buttons while pressing RESET and continue holding the A and B buttons for about 30 or 40 seconds until you hear a small *blip*. Then on the second controller
press and hold one of the buttons mentioned below and then press Start on the first controller to select a level.
Level 2 - LEFT
Level 3 - DOWN
Level 4 - UP
Level 5 - B
Level 6 - A
When your energy is running low, PAUSE the game and enter one of the following specific level codes.
Stage 1 - A, A, A, A, B, B, B, B
Stage 2 - A, B, A, A, B, A, B, B
Stage 3 - A, B, Up, Up, A, B, Down, Down
Stage 4 - Up, Down, Left, Right, A, B, A, B
Stage 5 - A, Up, B, Down, A, Left, B, Right
Stage 6 - Up, Down, Up, Up, Up, Up, Down, Up
Wait until the 'Press Start' text appears on the titlescreen, then press A, A, A, A, B, B, B, B, A, B, A, B, A, B, A, B. The text at the bottom of the screen turns red if the code is entered correctly,
but I honestly don't know what the code does.
Wait until the 'Press Start' text appears on the titlescreen, then press A + B + START to go to the sound test mode.