OK, I found the crystyal room, but the only thing I can shoot/buttstomp there is the green half of the half green-half blue ball. After shooting/buttstomping around the room, I go out of the caves, but again there are a blue and a red block when I fall down the hallway, I shoot the wall again and it again teleports me to my death. Is there anything else to destroy in the crystal room, and how do I go about that?

Much obliged!