Logical Cube with Balls (Falling Marbles)
The main idea of the Logical Cube with Balls (Falling Marbles) is to have a transparent cube or any other regular polyhedron filled with a number of moving pieces, balls or cubes (27 balls, for example). If we consider only 26 balls in a transparent cube, there is an empty space (the place of the missing ball), which makes it possible to move the balls by rotating the puzzle.
There are three key parts: the transparent case, the central piece and the moving pieces. The balls are colored as in the image and could be numbered accordingly. The central piece inside the case will form, together with the case walls, some ducts in which the moving pieces can be ordered in a logical manner (by color or by printed numbers).
The target is to rearrange the scrambled balls by colors (it is easier), or by printed numbers (it is much more difficult).
Patent no. RO 106962 B1 / 1993-08-30