To end the game and fight the witch you've gotta collect at least 810 notes. If you collect 882, it makes your fight a lot easier though. The 810 Note Door is past where you play the board game. Once through the note door, you'll see another jigsaw puzzle which kinda looks like grunty. Complete the puzzle and a big door will open.
Go through the door to find four note doors. One note door contains, an item that refillsall your eggs, another one contains an items that restores your red feathers, and another contains an item that restores your gold feathers. The fourth one contains another four piece jigsaw puzzle that'll double your health. Just jump in Dingpot to be sent to Grunty. Hope this helps!

well u go to click clock wood and go to the game thing in tree out side of click clock wood and jump in the sliverish collderen behind the game enterens.