The concept is simple: I will provide an original image at the start of the jam. Build a game based entirely around that image.
(The resolution of the image will not be known ahead of time, nor the theme, nor the type. It could be anything.)
Other images can be used incidentally, but the provided image (which can be scaled, rotated, etc. in 2D or 3D) should recognizably make up at least 50% of any on-screen pixels (flat-color background excluded, if used) at any given moment. Bonus points if no other images are used.
Spend an afternoon (or other 5-hour chunk of your day, depending on time zone) seeing what you can cook up!