The contest gets to an end and there is unfortunately no time to make any hardware improvements.
But i think it turned out pretty well. Game is working on two AA batteries and the BOM is quite low.

Also its reusable for any future software/game project : )
Lets see what the future holds.

Only thing i can improve for a next version would be:
Ditch the power button and make it sleep/wakeup on a button push -> Save 0,56€
Replace the two battery holders with a single one for two batteries -> Save 1,30€
-> New total cost of ~10,74€

Maybe add some additional Caps for protection. They cost almost nothing ...

However.

If you decide to use this project as a base: Have fun :D