In this game, SpongeBob has built a big sand castle where he is on top of it. Sand figures like horses, bulls, and giants created by Patrick are trying to destroy SpongeBob's sand castle. The player controls a bucket using the cursor. There is falling sand that must be collected in the bucket to fill it. A drop of sand collected earns ten points. Once the bucket has enough sand, it will glow, indicating that it is ready for use. Clicking on an area in the game will dump sand below. However this action will empty the bucket, so the player will have to collect sand again.
Dumping sand on the field will create a knight that acts as a shield against enemies. Dumping sand on enemies will destroy or damage them (but will still create a knight). Dumping sand near SpongeBob's castle will replenish some of its health. If the castle receives too many hits from the enemies, it's game over.
There are three kinds of enemies:
Horses are destroyed if they run into a knight, the castle, or if they get dumped with sand. They can take away half of a knight's health. Dumping sand on them scores 25 points.
Bulls can be destroyed in the same ways as horses. They are slower than horses but can destroy a knight with one hit. Dumping sand on them scores 50 points.
Giants can only be destroyed by dumping sand on them twice (this action scores 125 points). They can destroy knights with one hit and still be able to continue on. Once they reach the castle, they can land multiple hits on it until they are destroyed. Also they are slower than bulls.