In order to beat Robo Sandy, you have to jump on top of the robot
after it jumps in the air to try to smash you. Then jump again and
press the Y button to smash on the robot.
Once you do this 3 times, you switch to Patrick. Do the same thing,
but dodge the spring attack. When the robot's head falls of, pick it
up then throw it into the wires, then the robot will get shocked. Do
this 3 times, then you will switch back to SpongeBob. Do the same
thing again, but when you smash the robot, it will pick up it's head.
Then use the Bubble Bash attack to hit the button on the bottom of the
head. Do this 3 times and you will win. And for winning, you will get
the Bubble Bowl.

To beat Praun, you have to use the Bubble Bowl (oh, don't worry, you
don't have to fight them in a row). Dodge his attack and wait until
the grid has white lines and attack him. Do this 3 times and you will
win. Oh, he also sends out robots.