When the Going Gets Tough
From the Super Mario Wiki, the Mario encyclopedia
The first part of the level features an arena with a dramatic decrease in height. It features a few Smashers at the beginning, though two Ziggies and Hoppers each appear at the end, behind no particular cover.
The second part of the level features another arena with a dramatic decrease in height. A few Ziggies appear at the beginning of the area, though more spawn periodically along with some Lava Valkyries. Mario and co. must reach the area shaded in yellow to complete the level.