This trick involves the infinite rocket launcher (successfully complete the game; costs 1 million Pesetas). When you fight Saddler and Ada throws you the rocket launcher (special), take it, but do not use it. When you can get a clear shot to his main eye, use the regular unlimited launcher. Saddler will be killed and the rocket launcher (special) will be yours to keep. When you start a new game, you can sell it to the merchant.