It is a holiday mode that implements Christmas decorations and props to coincide with the month of December. As long as the mode is enabled from the options menu during this month, it adds:
New environmental props and changes:
Most characters and enemies wear winter hats.
Some places are decorated with Christmas lights.
Various-sized Christmas trees. The trees are climbable, making it easier to get to certain areas or escape enemies.
Some props, such as plush dolls and paintings, wear Santa Claus hats.
This mode was first introduced on December 2, 2022 for the game's version 1.0.2.0255.[1] Prior to its launch, the mode was found in the code script from the release of update patch 1.0.1.
