The microcontrollers should arrive on Monday, but since I had some time today, I decided to work a little bit on the graphical side of this. After all, we want it to look appealing. So I sat down with Inkscape and prepared this silkscreen for the front:

I will need to move that via for the "z" button. The buttons are labelled "o" for "accept/select", "x" for "reject/back", "s" for "start" and "z" for "pause". As usual, I spent about 15 minutes drawing it, and then another 30 fiddling with the nodes, trying to work around Fritzing's gerber rendering bugs. Also, had to rotate the actual PCB image up-side down, and then rotate it back in Fritzing — for some reason that fixes it. Don't ask.