5x5 TAK board, stones and case with magnetically attached lid.  The stones fit together so they don't slip around and the case holds everything in a satisfying layout.

To learn about TAK see: https://en.wikipedia.org/wiki/Tak_(game) 

Print 21 flat stones of each color,  2 trays of each color, 1 head stone of each color, 1 board, 1 case and 1 lid for the complete set.

Use 6×2mm Round Magnets  to attach the lid.

I glued a piece of ¼ inch yoga mat to the bottom of the case to keep it from slipping.  You could used any similar thickness non-skid material.