Super Mario World/Iggy's Castle

As you enter Iggy's Castle you'll appear in a room with a series of long fences. This place is great for acquiring additional lives. Grab the fence, and hit each of the koopas holding onto the fence from above. Note that punching any koopas through the fence (by pressing ) will reset the count, and prevent you from getting lives. There are enough koopas to get 4 or 5 lives in this screen alone. While you progress through the level you may notice the gap in the ceiling above the lowered fence and the suspended coins: there is nothing of interest above the coins as it is blocked.

Pillar peril
The screen in this area automatically scrolls to the right, with giant pillars dropping down trying to squish you. Avoid all the pillars by staying either at the far left of the screen, or the far right. Careful of the last pillar since there is a gap below it with moving blocks.

If you are Super Mario, on the way you will be able to get a Fire Flower from a flying block. If you are small it will only be a mushroom.

Once you reach the big red door, enter to fight Iggy Koopa.

Face off with Iggy
Inside Iggy's room you'll see a platform floating on a pool of lava, tilting left and right. To defeat Iggy, you must push him off the edge into the lava. Either jump on him, or shoot him with fireballs and he will slide down the platform. By hitting him only when the platform is leaning left or right, he can easily be forced into the lava.