Editing 1-A (NSMB)

Down the pipe you will see an underwater world. Also, a ?-block with a power up can be found. At this point the screen will scroll automatically: that means Mario will be crushed by solid obstacles if he was hit with that at the most left of the screen.Sushis, a kind of blue shark appearing first in Super Mario 64, will appear at both up and down at the screen, two each time. If it tastes one of Fiery Mario's Podoboos it will die quickly.

You could find a P-Switch while swimming along this level. If you hit it, it will produces silver coins between bouncy obstacles. Then, go as high as you can, to grab the First Star Coin, because Hidden Blocks, which populatesFrom there
Mario will go right, entering the pipe leading upwards, appearing near the
second Star Coin.

Upon entering the water area again, avoid the Cheep-Cheeps and hit the 
rotating Power-Ups for the picture that is on the block when Mario makes
contact from below.  Next up are Sushis attacking from the left, so dodge 
them and enter the Red Coin Ring to go try for the Power-Up/1-Up reward.  
The Sushis will now switch back to attacking from the right, but they are 
aided by air currents from pipes, so swim through the currents between waves
of Sushis, finding a P-Switch to hit, revealing a multitude of silver Coins
to grab, all the while dodging Sushi charges.

Swim right as soon as the Star Coin appears above, grabbing the Star Coin,
followed by either ducking to avoid the incoming Sushi or swim back out 
quickly.  Swim past the last few Sushis and head up the pipe, going forward
to jump to the flagpole to end the level!