Extra Bombs
On the Ship Selection screen, press C, A, C, A, Start, B. You will hear a chime, and when you start the game you'll have 99 bombs!
Extra Lives
On the Options screen, set Difficulty to HARD, Ships to 2, Continues to 1, and Sound to 65. When you begin the game, you'll have 99 ships!
Extra Weapons
On the Options screen, set Difficulty to HARD, Ships to 3, Continues to 2, and Sound to 77. While playing, you can press B on Controller Two for level 20 firepower!
Level Select
To pick any level, enter the Options screen. Now select the following sound tests: 1, 1, 9, 2, 2. A "Round" entry will appear in the options menu.
