...The Tough Get Going
From the Super Mario Wiki, the Mario encyclopedia
The first part of the level features an arena with six different platforms. Two Hoppers and one Smasher initially appear, though more spawn periodically. One Smasher spawns right at the battle entrance before the heroes take their turns.
The second part of the level features a linear arena. A few Bucklers appear in the foreground and Peek-a-Boos in the background, though more spawn periodically. Mario and co. must reach the area shaded in yellow to complete the level.