This is a little puzzle I invented (or at least I'm ignorant of other versions). The problem is to put all the pieces pointing in one direction, then get them all pointed in the opposite direction by turning pieces. It turns out it's fairly simple to work out.
Even though it's a very simple puzzle, it's kind of fun to just turn the pieces.
I've put a video up at https://youtu.be/yhvrXx4ZLu4
Print 1 gingkoBoard.stl and 25 copies of gingkoPiece.stl. On my Lulzbot Mini, it took 3 separate prints to print all the parts.