Catch only the pieces whose colour matches the square: white piece on a light square, black on a dark one.
Pieces fall down from above, above each one stands a square. Click a piece if its colour matches the square: white piece on a light square, black on a dark one. You let pieces that do not match fall through, that brings +10. If a matching piece falls through, you get −20.
The earlier you click, the more points. You have 5 lives: a wrong click or a matching piece reaching the bottom costs one. The more central the square, the larger the piece; small pieces at the edge bring more points. With every level it gets faster.