30 Lives
To start the game with 30 extra lives press UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT, B, A, B, A at the title screen. Now press Start for a one-player game or Select and Start for a two-player game.
Level Select
At the main menu press Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start, Start. If you did it correctly you should see a Level Select screen on the bottom of the screen.
SLAIUZ - Start with infinite lives
GXIIUX - Keep weapons after losing a life
SLTIYG - Become invincible-enemies don't shoot at you
PEIIXZ - Start new life with machine gun
ZEIIXZ - Start new life with flame-thrower
LEIIXZ - Start new life with spread gun
GEIIXZ - Start new life with laser
SXZGEK - Weird color code
