Every key has its own place on the screen, its own colour and its own note. Blue and low notes on the left, through the rainbow to red and higher notes on the right. The longer you hold a key, the wider the colour spreads and shimmers. Turn on the touchpad to paint and play with your finger too.
Drawings of Kyiv are hidden in the dark. Wherever your light passes over their lines, they light up in that colour and stay. Reveal a drawing and it slowly fades to black, then the next one appears.