Enter the castle and board a steel fence wall. Knock out Koopas moving on the fences in a row for points and hit the square gates to go to the other side of the fence. Red Koopas move faster than the green ones on the fences. After crossing lava pits, you’ll enter the door to the next room. In the next room, the scene side-scrolls and the ceiling will plummet down. After seeing the big red doors, go through them to take on the boss. The boss area is a seesaw boat over lava with Iggy Koopa laying out fireballs. Keep stomping Iggy until he hits the lava and you’ll finish. You’ll then find the first out of the 7 missing Yoshi Eggs.