Super Mario Bros./World 3

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.

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 kill the third goomba on the bridge, and leave the first two unharmed.
 * After the bridge, the block that's farthest to the left contains a star.
 * 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.
 * 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.

Part 3

 * After the four "?" blocks, the block second from the left contains a 10-coin block. Be sure to cash in on it.

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.

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.  Again, the "Kick and Run" strategy is your best bet.

Part 1

 * Wait for the Goombas to jump down to the lower island, and stomp on them.
 * The power-up is heavily guarded by the Troopas. Take your time, and try to power up without getting caught.
 * 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.

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.

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.
 * 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.

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.
 * 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 switch to finish him off.