It's a short puzzle-based story set in the same world as NITW but is billed as a supplement rather than a demo. What you'll find is a ghost story told by cats and enacted by you – a crocodile astronomer called Adina.
Talking about it too much would spoil the story but it has that spectre of death quality I remember being equally disturbed and intrigued by when I read the original Hans Christian Andersen tales. Plus you get to build little snowmen as part of the puzzle solving.
It's available as a pay-what-you-want game on itch.io, so if you've not played it over the Christmas break I'd say it's definitely one to earmark for a wintry evening in the coming weeks.