itch.io

Don't worry you still have time. How about a game where the screen is all dark, and you move around by having a light flash on and off so you can temporarily see where to go, but there are also enemies lurking that you cant see until the light is on, so its like a puzzle platformer. Or if you want to make something quickly just make a local multiplayer game, it will fit the theme no matter what because you are never playing the game alone but rather with somebody else.