All of the information below can be found in-game.
You must defend your castle from the careless beachgoers who would destroy it! Move about the battlefield using the left and right arrow keys. Dig traps for your foes using "X" and bury them alive with"Z". Traps must be sized to fit their victims! A hole too small is easily traversed. A hole too big is obvious and avoided. Your bucket can only hold so much sand. Use extra sand to build your castle with "Z". Create a glorious castle and rule the beach!