From the game:

"The object of the game is simply to occupy four colored spaces. There are 8 spaces to aim for so the task shouldn't be too difficult. Although the final task remains the same, there are four versions of Rithma that get progressively harder and finally allow you to play really deviously. For all the versions each player starts with four cube pieces of one color and chooses a target space (cyan, magenta or gold) to aim for."

The board is 7x7 squares and each square is either colored or has a shape in it. A piece moving off the shapes has to move the number of spaces that the shape has sides - 3 for a triangle, 4 for a square and 5 for a pentagon.