World B contains one difference in Super Mario Bros. The Lost Levels. Instead of green Super Springs, you will find red Springs that only launch you into the air for a very short time. This will likely change your progress.
Watch out! If you wait under a hidden block to stomp a Koopa, you'll jump with less height than you expected.
Hit the block above the first pipe to reveal a vine that leads to coin heaven C. However, only a super-sized character will be able to punch a hole in the brick in order to reach the vine before it scrolls off the screen.
A trio of hidden blocks in the gapped row of bricks make for a solid platform when they materialize.
Hit the "?" block on the far right and jump when the Power-Up Mushroom flies.
Instead of stomping the pair of Koopa Paratroopas in this section, you should target the pulleyed platforms for a better chance to advance.
Pop the "?" block as you ride the sliding platform in the middle of this section, and grab the Power-Up Mushroom before it drops. Then, secure your footing on the platform or the block and jump to the next challenge.
If your character is super-sized at the end of this section, hit the bricks quickly to clear away one and make a Fire Flower appear in the other. However, you need to collect the coin above the power-up block before hitting the brick itself. Otherwise, the power-up won't appear, yet the block is still emptied.
Riding the sliding platform at the very beginning of this section is the only way across the gap. If your hero is super-sized, he'll have to duck in order to squeeze under the bricks.