These
darts do very little damage, and Twinsen can only carry up to three of them, but after thrown they can be picked up again.
Darts aren't very usefull in through the adventure, but they are used in the duck shooting game of Temple Park, and shooting darts at FunFrock's bust in the basement of Twinsen's house which makes life candies appear.
Darts can be bought at Mr. Bazoo's shop, at the shop in Port-Ludo, or at the duck shooting game in Temple Park, for 4 kashes. They are also found in Twinsen's basement.