I feel like this would be easy and festive.

Trick-or-Treaters in houses all around Graal, each bearing some spooky dialogue. Some (the treats) will give you a few gralats, while some (the tricks) will take some gralats from you! All just a simple game of chance to keep people occupied and having fun trying to guess the tricks and the treats. Plus, every NPC should wear a costume for the occasion! Sounds like fun to script, and also fun for the Graalians! Critique?