A Power-Up, a 1-Up, and a Starman are yours for the taking. Grab the items that you need, then dash with invincibility past the Hammer Brother ahead.
Another massive 1-Up opportunity presents itself here for expert players. Trap the Buzzy Beetle along the right side of the first platform by creating a mini-staircase. Then jump up and hop on top of the Beetle so that it bounces off the right block, popping you back up in the air while you accumulate points, and eventually 1-Ups.
If things don't work out with the Buzzy Beetle, you can try again with the one of the Koopas on the third platform, after the jump
The 1-up is only available if you don't hit the flying Koopa and it is in the center of the U shaped blocks
If you're in need of a Power-Up Mushroom, knock out the one in the fourth Coin Block from the left, then run to the right and catch it on the fly.
The wind will start to push you to the right when reaching the stairs. Use this to your advantage to clear that long gap.
Alternatively, you can try to reach the pipe under the solid brick platform. Jump to the first falling platform and face left quickly. Once the Red Piranha Plant is gone, jump and drop down to reach swim area B.
Limited memory will incredibly affect the map here!
Because the console will only allow a maximum number of sprites at a time, this may affect the number of enemies and platforms. Only five moving objects/enemies excluding your player can appear at a time on your screen and half a screen ahead of you. This affects the three columns of platforms in this area.
As long as there are one to three enemies on the screen, you will notice two platforms in the column that follows.
If four enemies are on the screen, only one platform will show up in the column ahead.
If five enemies are on the screen, no platforms will show up at all! This means that some other enemies will not show up either until others disappear.