Level - Filament
This is in the very first zone and you will need to choose the character Holly. Using the screenshot below, position yourself in the top left corner and press the
to switch to your cannonball weapon and aim in the same general direction as I have. Then fire it as you would a normal weapon. If done correctly, the cannonball will drop in the hole. Can try this as often as you like before the level ends, but I'd recommend clearing as many enemies as possible before attempting it.