A guide to completing World 3-6 in Super Mario Bros 3 for the Nintendo Entertainment System.
How to Clear World 3-6
This level will automatically move from right to left, so make sure to keep moving so you don't get pushed off a ledge or crushed by a wall.
Go to the right and jump on the Donut Lifts. Hit the ? Block to get a Super Mushroom or Fire Flower. Then jump onto the wooden platform, and from there jump onto the Rotary Lift right after it stops spinning. Then jump onto the next set of Donut Lifts, and finally, jump onto the wooden platform to the right.
Next, there are coins that you can get, but you have to be quick. As soon as you can see the Red Koopa Troopa on this platform, stomp on it and pick up its shell, then stand on the Donut Lift and let yourself fall until you can go to the right to land on the lower wooden platform. Then quickly kick the shell between the ? block and the Donut Lift on the right. The block contains coins. Wait as long as possible before you jump over the bouncing shell and land on the Donut Lift on the right. Then jump from that Donut Lift to the one above that, and from there to the next wooden platform.
Next, pick up the ice block and throw it to the left, then quickly stomp the Koopa Troopa, pick up its shell, and stand on the Donut Lift to fall below. Kick the shell through the Koopa Troopa so it hits the brick on the lower platform. Try to dodge the shell or shoot it with a fireball as you collect the three coins and run over to get the Super Mushroom or Super Leaf that came out of the brick. Then jump straight up to break the brick, jump through the hole and get the three coins on the left, and if you're Raccoon Mario now, hit the brick on the right with your tail.
Jump to the next platform and hit this brick with your tail as well, and stomp or ignore the Red Koopa Troopa, then jump to the Donut Lifts on the right. Pick up an ice block and kick it to the right to hit the brick, which contains a P Switch. Then jump and hit the bottom-left corner of the coin above you to make a 1UP Mushroom come out. Go to the right to get the mushroom, as well as the coins that have appeared, but dodge the Green Paratroopa.
Finally, wait for the bricks above the Donut Lifts to turn back into coins, and collect them, while dodging the Red Paratroopa. Go from there onto the Rotary Lift, then jump down from the Rotary Lift onto the pipe below, and go down the pipe.
Go to the right and get past the Green Paratroopa, then keep going to the right to reach the end of the level. Hit the Goal Block to complete the level.
Next, you can go to World 3-7 or (if the bridge is down) World 3-8.