Shoot Two Elec Balls using One Ammo Piece:
Get two Elec ammo pieces and using Danny's Slingshot hold 'Shoot' and you will fire two Elec Balls while only using one ammo piece'

Defeating the First Boss (Big Robot):
Go over to the side without falling off and shoot his arms and lasers as quickly as possible on each side saving time and health because if you get hit by lasers while doing this you will only lose a small amount of health.