Green Star #1
The first Green Star requires that you light the eight unlit torches in the dark opening area of this level. You can get a Fire Flower from this ? Block in the beginning. If you’ve done this, the last torch you light should be next to the pipe leading away from this area, and the star appears close by.
This upper area used to have more significance the first time you were on this level. Now, it provides some extra Coins and even a 1-Up from a ? Block, but it’s nothing that is crucial to explore.
Green Star #2
This next section provides more torches to light up so that you can retrieve the second Green Star, starting with these two. There are 12 total to light up. Princess Peach can make lighting the torches a lot easier, thanks to her ability to float.
The path you must take to accomplish this is challenging, thanks to the moving platforms, the ever-present Poison Bog, more Piranha Creepers, more Fire Piranha Plants, Fire Bars, and Parabones. This is arguably some of the hardest platforming you’ve yet seen in the game. A common mistake here is to forget to light up the torches occupied by the Fire Piranha Plants.
The small drifting platforms are spaced far enough apart that you may have to resort to long jumps to keep away from the drop off on the right side of this area. Between that and dealing with the Piranha Creepers, this section is possibly the hardest in the whole level.
If you manage to light all the torches, the Green Star appears near the pipe that takes you to the Goal Pole zone.
Green Star #3
The steps leading up to the Goal Pole have three unlit torches, and Piranha Creepers lurk in between each step. Take care not to lose your fireballs and ignite the torches for the final Green Star.