Part 1

The second pipe is the entrance to coin room C. You can enter the coin room by jumping on top of the pipe and pushing the "down" button.

Unlimited 1-ups

On the stairs near the end of World 3-1, stomp on the second Koopa Troopa. Jump down to the next lower step. Leap and hit the left edge of the shell to knock it into the step.

Part 2

There is a 1-up hidden above the right end of the bridge. In order to make the 1-up appear, you must collect every coin in World 2-3, or use a warp zone to reach World 3-1.
After the bridge, the block that's farthest to the left contains a star.
In Vs. Super Mario Bros., a Koopa Paratroopa is added along with that green Paratroopa which is changed to red.
It's time to wage battle with the Hammer Brothers. If you proceed carefully, avoiding the flying hammers, you should be able to get past them. It is easier if you collected the star a moment ago.
The Springboard can be used to get the blocks above the pit, but there is a better way. Use to accelerate, and jump between the two sets of blocks. Punch the right block and find the beanstalk that leads to coin heaven B. Once the beanstalk is out, you can jump down to the left and use the Springboard to get to the beanstalk.
In Vs. Super Mario Bros., be careful when reaching the springboard. It is between two pitfalls and on one block, so it is very difficult to use the springboard to get in between the two sets of blocks. Unfortunately, the beanstalk is a better way in this version of the game. Finally, the top platform with the powerup is all "?" blocks.

Part 3

After the four "?" blocks, the block second from the left contains a 10-coin block. Be sure to cash in on it.
In Vs. Super Mario Bros., the 10 coin block is omitted. Followed by an extra pit and the pit near the steps is longer. Also the infinite 1-up trick is omitted as the Paratroopa are replaced by goombas. Finally, the powerup is now on the top right row, which is now all ? blocks as well as all the other rows.

Expert gamer!

On the steps to the flag, an expert player has a chance for "infinite" 1-ups. If you catch a Koopa Trooper on the edge of a step, knock him into the back step over and over while keeping Mario above the next step down. This takes a few tries to master.

World 3-2

Part 1

You must deal with a lot of Troopas and Goombas here. The "Kick and Run" strategy is the best way to score. If you're good, you can go for the extra life bonus.

Kick, run, accelerate

At this level, after you've stomped on the turtles, kick them and then chase them. With skill, you can destroy a lot of enemies, and you might even pick up an extra life!

Part 2

There is a star in the top block and a 10-coin block on the bottom. Since the Troopas on the ground are dangerous, it's better to get the star before you get the coins.
In this section and the next, the enemies appear in great numbers. But it's a great place to score a lot of points. Stay for a moment next to the pitfall till the star effect ends, then don't miss the first Troopa to meet after the next pitfall and use the "Kick and Run" strategy to get a 1-up out of the killed enemies. You will be able to listen to the sound of the 1-up after killing all the 9 Troopas.

Part 3

After the Koopa Troopas wait for the piranha flower to get in its pipe. Grab the four coins hovering above it, then jump down and avoid or kill the five Goombas. Proceed to hit the flagpole.

World 3-3

Part 1

Wait for the Goombas to jump down to the lower island, and stomp on them.
In Vs. Super Mario Bros., that Goomba is replaced by a flying Paratroopa. The lower islands are smaller in the lift section.
The power-up is heavily guarded by the Troopas. Take your time, and try to power up without getting caught.
In Vs. Super Mario Bros. look out for a Paratroopa on that high island.
Mario's weight will make the last lift in this section sink. Jump to the island to the right as fast as you can, or you'll go down with the lift.
Watch out at the end of this section. Don't jump down to the lower island, because you can't get back up. Stay on the upper islands, and collect all the coins that you can.
In Vs. Super Mario Bros., also watch out for the Paratroopa on the left and highest island just before the lifts.

Lifts, lifts and more lifts

Lifts are found throughout the Mushroom Kingdom, but they are most common in the tree top worlds. There are many different types of lifts: 1) Horizontal which move left and right; 2) Vertical which go up and down; 3) Elevator which continually move up or down; and 4) Balance which work like a see-saw--Mario jumps on one end and it goes down while the other end goes up. But beware, some lifts just drop down when Mario lands, so be prepared to move fast.

Part 2

Use maximum precision to clear the horizontal lifts. First, use one of the balance lifts to get to the lower horizontal lift and then hop to the small island. Once on the island, you can accelerate, and jump to the treasure island with the coins.
Defeat the flying Paratroopas before you attempt to cross to the right.
The balance lifts located just before the end makes it hard to jump to the top of the pole, but there is a way. Stay on the left lift until the lift on the right rises. Use to accelerate. Jump to the right lift, and then on to the top of the flag pole.
In Vs. Super Mario Bros., the lowest island directly before the last treetop with the two red koopas are omitted.

World 3-4

Part 1

Poboboos shoot out of the multiple pits, so clear them with utmost caution. Time your jumps carefully, and cross the area when the fire-bars are pointing down.
In Vs. Super Mario Bros., before you get to the Power-up look out for 2 extra lava pits and a firebar on top of the ceiling in between the 2 lava pits.
A set of fire-bars rotate in different directions, starting at the end of this section. Needless to say, they are deadly. Stay to the left and watch for a while to learn their movement patterns. Then jump with care.
In Vs. Super Mario Bros., to make it even more difficult, there is one block of a lava pit on each side of each set of fire-bars.

Double fire-bars? Jump!

Single fire-bars are easy to handle once you get the hang of it, but double fire-bars are another story. The only way to clear this kind of hazard is to accelerate, and jump over it. The lower bar can be avoided easily if you time your jump correctly, so concentrate on the higher bar.

Part 2

The pits are close together, and you'll be constantly bombarded with Bowser's fire breath. If things get too hot, seek refuge in the low spot to the right, just before the drawbridge.
In Vs. Super Mario Bros., there is a Troopa after the first Podoboo and another after the last Podoboo.
In Vs. Super Mario Bros., there is a pit fall to the right of the low spot, just before you reach Bowser. Also after that pitfall two out of the next four blocks have a gap so you'll need to run through that.
Once again, blocks hang from the ceiling over you and Bowser, which makes jumping risky, but not as much as it was in World 2-4. Just hit the axe to finish him off.