After pcb etching it was time to solder the components. I made a short stop-motion animation of the build:

Soldering did not take very long and next task was to flash software to the microcontroller. I used an adapter consisting a row of test pins to attach pcb test points:

It works!

I made light guides to the top cover using hot glue:

Light guides worked really well, but red leds were too bright and they glowed through the casing, so I decided to print the case with different colors. I chose black for the top and red for the back case and for the button. I think they came out pretty good.

Wires are quite ugly, because I did not have long enough grey wires. I might change them to another color if I need to add connectors.

Now I just need to test controllers in the actual environment.