Extra Options...
	Extra Ships...
	Full Power...
	Level Select...

Pause the game and press Up, Up, Up, Down, Down, Down, Left, Left, Left, Right, Right, Right, C, C, B, A. This only works once per game.

Pause, then press Right, Down, Right, Down, Left, Up, Left, Up, B, C, A. This only works once per game.

For maximum cannon power, pause the game and press B, B, C, B, B, C, Up, Down, A. This only works once per game.

To start at any round hit Reset ten times, then hold Down-Left and go to the Option mode and you will get a Level Select option.