After Playing Hide-and-Seek with Grandma, Who Had a Brief Rally Before the New Year, Our Whole Family Disappeared

A Director-Type Story About a Copycat Author

I read this book before but can't find it now. The protagonist has a System that only lets them make horror movies. Horror as a genre is almost nonexistent in this world, and the first film they make is The Old Corpse in the Mountain Village, which establishes the ghost movie genre. Later on, the restriction disappears and they start making other kinds of movies.