Spongebob is being assaulted by anchovies and he has to avoid them at all cost to have all the power built up when the robot comes along so that you could defeat him.
Rapidly press spacebar to raise the power gauge while Plankton's minions approach. When you kick the robot anchovy into oblivion, throw plates, burgers, jellyfish to make the robot bounce further! Watch for the limited ammunition number in contest mode. Only a small additional amount is granted at each new level.