The basic shape of the ENI is cylindrical. The cylinder is divided by several “ring-shape sections.” These sections can rotate independently. Each ring section includes multi- individual parts, with one piece missing. These parts can travel along each ring by using the missing piece (empty space). By rotating and sliding the pieces in and out of the empty space, a multitude of solutions is possible.

The object of the puzzle is to place the tiles into patterns by making the rotating and sliding moves that manipulate the empty space.

The difficulty of the game is very normal and medial. This is a real puzzle that can be solved without knowing a pre-set series of moves. There is no algorithm, this is a problem solving challenge; just like a jigsaw or sudoku puzzle. No batteries or accessories required!