I Have One Day a Month to Do Whatever I Want

A realistic sandbox world. On the last day of each month, the world stands still, and only the protagonist can move. He can do whatever he wants and treat the entire world as his own private sandbox. He originally wanted to enjoy this bug to the end of time, but it turns out that other people can also move, such as the End-of-Month Man, the Faceless Man, the Parasite, the Gravekeeper, and so on, who will appear in turn.