So ya wanna find out how to get the fun ending?
Well be prepared, its gonna be a ride!
First, go to the haunted forest and input these directions: Left Left Right Left
You should come to a secret area, accept to his challenge. Then you wanna go back to the forest and to the monke hq
If you dont know how to get to monke hq, then input: Right, Left, Left, Left.
Go to the shack. You should get the key.
The game should take you back. Accept to the battle. Heal as much as you can (Him healing doesnt matter, just heal to any amout. He does 60 damage each time.) When you have hp your comfortable with, start picking the tire option. After tiring him enough he will go to sleep and you get a shard.
Go to the town and get the gun, then go to the weed man and kill him. Go to the forest then get into the shack, unlock the basement. Normally this would be the mystery path, however since you have the shard you can pick to use it. Once its used, you just need to leave the basement.
This wouldnt be fun to speed run since inputing the directions would be a tiring process, and figuring out the optimal strategy in the fight would just be exhausting.
Edit: I created a youtube video, it should help.