Click "New Game" when the background animation is flashing white at the title screen to start with five bombs instead of three.
Invisibility
Press [Ctrl] after taking off in level 5 to display the console prompt. Type go0gleypower as a code to become invisible in level 6 for about 25 seconds.
Level 3: Hidden extra life
There is a blue box with a question mark just before the harbor. Do not shoot it or lose a life. When the tank exits its base and breaks the box, an extra life will appear.
