Kickle Cubicle

Extra levels:
Enter FbgJ IYAX or GdBM IABg as a password to play additional levels.

Kid Niki:
Hold A on controller two at title screen, until Kid Niki appears.

Sound test:
Hold A + B on controller two at the title screen and press Reset. Press A or B to select a sound and Up, Down, Left, or Right to play them.

Preview first Boss:
Hold Down and power on the NES. Press Up on controller two after the screen turns white.

Special game:
Hold Select and power on the NES. Press Up on controller two after the screen turns white.

Suicide:
Press Select during game play to end the current game if you become stuck.