At the beginning you need to dodge or, as a Tanooki, kill the Roto-Discs to get to a pipe taking you up one floor. One of the Roto-Discs rotates around a block holding a raccoon leaf.
At the top, pass the Thwomps and get to the pipe to arrive at part 2.
Part 2
Watch out for the Pile Driver Micro-Goombas here. Either dodge them into the pit, or jump on them to kill them.
If you're Raccoon or Tanooki Mario, on the middle tower wag your tail against the middle brick block for a 1-up mushroom.
If you have a P-Wing (and only if you have a P-Wing), you can fly over the entire brick block structure to get to a hidden area on the other side with three 1-up mushrooms. They're however insanely hard to collect since you cannot see anything, as the screen won't scroll there.
As Raccoon or Tanooki Mario, wag your tail against the brick blocks next to the pipe for some coins. Enter it to get to part 3.
Part 3
Carefully jump over the spike pit and avoid the Thwomp and the Roto-Disc. The pipe takes you up one floor again.
The top area is empty, so just enter the pipe there to get to part 4.
Part 4
Again, if you're Raccoon or Tanooki Mario you can wag your tail against the brick blocks next to the pipe for some coins.
Watch the Koopa Troopa when you jump onto the clouds. Jump at the only brick block to reveal a vine.
Climb it up, then go through the pipe there to finish the level and appear in the sky part of this world.
5-4
The first block you see contains a raccoon leaf. As Raccoon or Tanooki Mario, you can use the initial platform to take flight. This will take you to cloud platforms in the sky with some coins on them. You can start flying from here to skip the entire stage.
The first three lifts spin around endlessly, so jump over them to avoid them. The next one does not spin around, but moves when you jump on it, similar to a scale. Jump to the next, spinning lifts while they spin so you land on them exactly as they stop, then cross the area to get to the next cloud platform.
The waterfalls can give you some difficulties. Press A repeatedly to avoid getting pushed down into the abyss.
Watch the green Para-Troopa when you jump over to the pipe. It leads to the ending area, where Lakitu is waiting for you. You can get a free 1-Up if you wait until he drops four Spinies and then get the card, but this is not easy.
5-5
This level is largely made of donut blocks, which fall down if you stand on them too long. Therefore, keep jumping or running and only rest on solid blocks.
You should absolutely try to avoid the Micro-Goombas. They can really screw you over in this level.
There are a total of four raccoon leaves in the entire level: the first one is hidden in the top wooden block before the pipes, the second one is in the first ? block, the third one is in the rightmost brick block near the end, and the fourth one is right next to the third one inside a wooden block.
There are two pipes blocked off by brick blocks. The right one leads to a bonus area (see below). Either use Raccoon Mario's tail, or a Koopa shell to destroy the brick blocks.
You'll see a new enemy in this level: a Fire Chomp. They're similar to Chain Chomps, but fly around the level and shoot small flames at you. You can simply stomp on them to kill them.
Collecting 28 coins (i. e. every single one) unlocks the White Mushroom House. This requires getting into the bonus area, and also collecting the set of coins under the donut blocks.
Bonus area
Jump at the giant ? block to get a Tanooki Suit. Exit the area to end up near the end of the level.
5-6
This autoscrolling level is the only level in the game with Para-Beetles. These shells fly to the left, but carry you to the top when you jump on them.
If you can't fly you'll have a hard time jumping from shell to shell to cross the pit. It requires very precise jumps to land on the shells as they move.
The first block you see contains a raccoon leaf.
Once you see brick blocks, jump down to the bottom row and jump at the second brick block from the right to uncover a P-Switch. Step on it and the coins will form platforms that lead you to the end. Just watch out for the Fire Chomp wandering around there.
The ending area has a Lakitu just like 5-4, and you can do the same 1-Up trick here.
5-7
If you have a starman in your inventory, use it and then enter the level. This allows you to make use of the continuous starmen scattered across the entire level, which makes it very easy to beat.
The wooden block right at the beginning contains a Fire Flower.
This level is full of Pile Driver Micro-Goombas, which you need to watch out for. However, they shouldn't pose a big threat.
Beside the pipe with a Piranha Plant inside, the leftmost block contains a 1-Up mushroom. If you have a P-Wing, you can also enter the pipe to go to the bonus area (see below).
In the second half of the level, Lakitu will join the party. He can give you some trouble since you may accidentally jump into him.
The pipe at the end takes you into the ending area. Again, you can do the 1-Up trick here.
Bonus area
If you have a P-Wing, fly up to find a P-Switch, step on it to transform all the brick blocks into coins. (It is too high for you to fly to normally, which is why the P-Wing is needed.)
Of the last column of wooden blocks, the topmost one contains a raccoon leaf. One of the note blocks contains a normal starman, which you can use with the continuous starmen if you wish.
