Come to my Discord, please.
It'll be easier to help you navigate through the game.
https://discord.gg/JyaBXfntcx
If you beat the crab at the waterfall you can go up the door through the waterfall, once all of the blue blocks are on the gold switches.
Sorry. I just found the last block needed in a part of the map I didn't notice near the beginning of the last part. I thought all the blocks were just for the stone doors to be gone. Didn't realize that one would unlock the door
