In you neighborhood on Halloween night there is a old house with a man standing outside. He offers a challenge to you :

If you can make it to the top floor of the house behind me I will give you as much candy as you want. But be aware this house is haunted and monsters live inside. You must avoid them as you make it to the top.

Seeing a way to get more candy then you would trick or treating around the neighborhood you accept the challenge and head inside.

Source Code: https://github.com/Zoey-21/Trickortreat_house

Was apart of the Trick or Treat Jam: https://itch.io/jam/trick-or-treat-jam/rate/1245908