Shooting in virtual space is an optional condition to kill someone, but you definitely need to hit some target, and in the case of Fire Balls - Shoot Ball 3D - these are towers made up of discs. They are located at the intersections leading to the chest of gold. It is necessary to shoot from the block cannon, breaking disc after disc, until there are none left as a reward, you get a large blue crystal and a free path to treasures. But they are all so simple. As they say. Black fragments of a circle constantly revolve around the tower. You must not hit them or Fire Balls - Shoot Ball 3D will end.