Some improvement last days:

- I could put all circuits inside the Tic Tac case;

- Small update in software. The minimum viable game is done.

Next steps:

- Circuit to measure the batteries power level. It may show a small icon on top of the screen, just like an smartphone;

- More buttons (all four directions, plus two action buttons);

- Transparent case would be more cool than this orange partially transparent;

- Back light (is it really needed?). The 5110 display has this feature, but I'm not using for now, because of power saving reasons;

-Software reset (pressing the two buttons for 3 seconds). There is already a Hardware Reset: a small hole in the case's back to press the Arduino reset button;

- More than one game pre-loaded (I'm not sure if the small memory of Arduino Nano would be enougth).

- Many other things that I don't remember right now.

Pictures (what really matters):

And a video:

Thanks for reading.