Knowledgeable Yolk

My version comes with tiles stacked above one another.

The best strategy here would be clearing tiles from the upper level first.

If this is not followed then the player would run out of moves.

Tiles that are in between a line cannot be moved unless one side is freed and unless the upper layer tile positioning exactly above it is already played.

I play this one. It’s called Vita Mahjong. Available on the play store.

Billions must be out of service…