The object of the game was to blow up all the attacking Cylon Ships and then return to your mothership. You had a limited amount of Fuel, and in most of the later 'Attack Waves', you would have to return to refuel. Some of the more interesting aspects to the game were the fact that larger 'saucer' type ships would spawn drone ships, and collectively they would all attack your mothership when you refueled. Should your mothership lose all her shields, that's game over. Should you lose all your shields, then that's Game Over too.