For graaloween, really just a mix of what everyone likes, but balanced to it won't be super boring, and too difficult. Allowing even casual/new players to get something.
Candy shards or candy pieces, 5 pieces = 1 candy. 10% chance to get a chocolate piece.
Collect enough of them to form a whole candy. You can collect them by catching ghosts, entering houses (limited to 10 per day).
There are different colored candy pieces, so you can trade with others to complete your set. If you have 4 green and 1 red, then you trade with someone who needs that red piece, for their green piece.
To turn in your candies, there will be multiple npcs around the map. 1 candy = 10% chance for a treat, 90% chance for a trick.
Collect chocolate pieces for rare items. 10 for 1 chocolate.
To turn in your chocolates, there will be a building where the spiders are located (by master li's entrance)
Top 3 candy collectors will win trophies and trophy furnitures.
Top 3 candy givers, same thing (Melting Chocolate House)