Here's a bit of cultural worldbuilding and dynamic movement practice.

Strike Team: Those with the sticks will attempt to outmaneuver each other with the ball in order to approach within striking distance of the opposing team's sandcastles. Their objective is to shoot the ball at the sandcastles in order to knock them down. The attack teams are the ‘heels’, so to speak, often acting out a villainous on-field performance in their sinister masks. They are older and stronger than the build teams in order to further enhance this impression. They are the spirits of destruction and war, after all. They are booed. They destroy all of the hard work done by the build teams, and their shots are met with gasps of dismay. Attackers need to be fast, strong, and alert. Strikers are encouraged to wear fearsome decorations and to menace the spectators. Each team fields three, usually with one or two backups in case of injury.