Press the 'Caps Lock' key on the player select screen (another source says: press the 'Caps Lock' key on the player select screen, so the key light is on. Now press and hold the 'Caps Lock' and press 'Fire') and a message appears. Start the game, and lo and behold, MORE LIVES. If you hold down the 'Fire' button a little too long, the game may start and bypass the message, but you should notice you have a lot of lives.