The term is also used for long-form content intended for offline use:
Players are trapped in a nightmare scenario (often a school) and must find a way to escape within a 12-hour in-game limit. 12 Hours Free Download
The phrase is most commonly associated with time-limited gaming promotions or specific media titles that center on a twelve-hour timeframe. Because it is a broad term, the "proper write-up" depends on whether you are referring to a limited-time offer, a specific video game, or a film. 1. Limited-Time "12 Hour" Promotions The term is also used for long-form content
There is a specific indie horror/survival game titled . a specific video game