Sundown
some drives are the whole point.
a coast road with nowhere to be: hold to drive, let go to coast, and the sun goes all the way down while you do
Your thumb only changes how far you have gone, and that alone sets the sun's height: the sky, the sea's colour and every shadow follow from it. Drive far enough and the sun sets; nothing was ever at stake.
Concepts: light, time, perception.
An interactive you play with one thumb, on Wundr.