Play the game, get a highscore, and kill yourself.  For your name,
 enter 'NANCY' and hit return.  Now when you play again you will have
 unlimited lives!
 
 Another untested method is to select your player, start the game, and
 kill yourself off.  Then play again with the same character, and
 while the game loads keep hitting return.  This should also give you
 unlimited lives.