Pause the game and place a steel ruler on the round table as a mirror. Marbles roll in a straight line, bouncing off the ruler at an angle equal to the angle of reflection. Successfully place all the glass marbles into the central well to pass the level. Clicking on the short, medium, or long ruler will immediately display the steel ruler on the table and keep it selected. Dragging it adjusts its position, and rotating it 45 degrees rewrites the trajectory. Marbles will fall off if there's a gap in the table edge, and failing due to timeout or repeated blank shots will also result in failure. Each level has a limited number of rulers; some levels only allow the short ruler. Freeze the game, place the rulers, and then start rolling. Twelve main levels plus a daily level are suitable for players who enjoy geometric reflection and short, strategic thinking.
