Hard game, sure !

thingiverse

This is a cube I call blackbox, printed on a 10 cm side length, about 4 inches. It's a labyrinth used with a metal ball, 20 mm in diameter or 4/5 inch. Your goal is to get the ball from the front door to the back one. Be warned, it's much harder than you think! This cube, named blackbox after the tool used by physicists in nuclear research... (a particle goes in, will it come out but where?) is printed at a size of 10 cm per side. By placing a metal ball or other object with a diameter of 20 mm, your task is to get it out the other side without seeing it. It's much harder than it seems. Your only guides are the sensations of the ball's movements and the sounds you hear.