What am I supposed to do in the boss fight against the giant skull? I thought I needed to make the projectiles hit the skull, but nothing seemed to had happened.
I also got to the second phase on one run, and I don't know how.
EDIT: Turns out that I needed to stand on the pads that shoot out fireballs while they're still flashing white Be next to the boss to let it get hit by the fire that appears close to me.