the rules of the game
Start with an empty game board - consisting of the four separate blocks. The starting player choses a colour and then places a marble in a socket of their choice.
After placing a marble the player turns any one of the four blocks one notch (90 degrees) clockwise - or anti-clockwise. A board, not necessarily the one on which the marble has been placed, must be turned on each move.
Then the second player does the same, i.e. places a marble and turns a board. So on and so forth.
The first player to get five marbles in a row wins!
The row can be horizontal, vertical or diagonal and run over two or three boards. If a player gets five in a row when placing a marble they do not need to turn a board. If all the sockets have been filled without any player getting five in a row the game is a draw. If both players get five in a row as a player turns a board the game is also a draw.
That's it! Simple, yet brilliant.