|World location||Yoshi's Island|
|Previous level||Yoshi's Island 4|
|Next level||Donut Plains 1|
|Game(s)||Super Mario World|
At the start of Iggy's Castle, the player must move around by crossing over the large fence. There are also areas where the player hit a loose part of a gate in order to flip over to the other side. There are also Koopa Troopas that move around on the gate and Podoboos that jump over the lava. After making past the gate section, the player can cross over the checkpoint gate and use the door to head into the next section. In the next section, there is a large object that comes down and tries to flatten the player. The player can avoid this by ducking into one of the lower areas of the platform. The player must be careful as being crushed by the object results instant death. After getting past that area, the player can now fight Iggy Koopa where the battle takes place on a platform that rocks back and forth over the lava. The player must either jump on Iggy's head or hurl fireballs at him until he sinks into the lava. Iggy may also sometimes spit fireballs to throw off the player. After Iggy Koopa is defeated, his castle is destroyed and the way to Donut Plains is opened.