I just beat Balrog for the second time, rescuing the robot he so callously crushed. And, good news! He'll build a bomb for me so I can free the voice trapped in the closet!
He wants Charcoal, a Gum Base, and a Jelly Jar - I know how to get the Jelly Jar, but the Charcoal and the Gum Base elude me.
I did find a door with the word "Gum" written on it, but the door is locked, so I'm unsure how to get through if that is where to go.
I have no idea on the charcoal.
Where can I find these items?
(I'm playing Cave Story+, if that matters)