From the box:'Spiralball has a unique shooting action. The marbles are fired from the spring-action mechanism and enter the spiral channel which then launches the marbles swiftly in an arc toward the scoring holes. Of course, the plastic dome does contain the high flying careening sphere.You gotta know just how fast or slow to shoot those balls so you can get in the high scoring holes and it's easy to keep score 'cause the balls always roll into those scoring slots with the numbers.'Game appears to be a contained 'skeeball' set with 9 marbles in it. - BoardGameGeek