Per default the box particles fly around, and bounce off each other and the world's borders and can "sucked" around with the cursor.
Additional stuff is controled through the keyoard. Typed letters draw a pixel font image to a PGraphic and based on that the boxes get moved around. The other effects mix usage of the PGraphics, particle velocity or direct placement.
The countdown gets started by typing "`" + two digits + "cod".
Down in the bottom you can see the currently entered textstring.
The font was designed by me with fontstruct.com