How to clear Vanilla Dome 2 in Super Mario World for the Super Nintendo Entertainment System and Game Boy Advance.

How to Clear Vanilla Dome 2
After you fall into the water, go to the right, but watch out for the Cheep Cheep that is bouncing on the ground. To the right, there is a Buzzy Beetle. Next, there are four Prize Blocks that you can hit from underwater. The second Prize Block from the left contains a Super Mushroom or Fire Flower, and the rest contain one coin each.
To the right, there is a Cheep Cheep swimming up and down. Swim to the right and you find another Cheep Cheep swimming up and down. Hit the Block to make a Beanstalk appear. Climb up it.
At the top, go to the right, where there are two Buzzy Beetles, followed by a pit in the ground with a Buzzy Beetle in it.
Go to the right and fall through the coins and Dragon Coin, then swim right, past two Cheep Cheeps that swim left and right. Next, you reach an area with Cheep Cheeps that swim up and down. There are three Prize Blocks in the middle. The rightmost Prize Block contains a Cape Feather. To the left of the Prize Blocks, there is a hidden Prize Block against the wall, just below the coins. It contains a 1-Up Mushroom. You might not want to collect all the coins above the Prize Blocks, because they can be helpful if you use the P Switch that you will find later in the level.
To the right, there are two Cheep Cheeps that swim left and right, and a Prize Block above the water. It contains a Fire Flower. Jump onto the Brown Block and jump onto the ledge on the right, then jump to the ledge on the left, getting the two coins and Dragon Coin on the way.
There are two Buzzy Beetles to the left, followed by a P Switch. Don't hit it where it is, or you will fall down into the pit of coins and won't be able to get back up unless you bounce off a Buzzy Beetle or just wait for the P Switch to run out. Instead, take the P Switch to the left, collecting the wall of coins. Hit the Prize Block to get a Fire Flower. Then step on the P Switch and collect the coins on the left. If you want to go to the secret exit, jump over the gap and fall through the nine coins in the next gap. When you land in the water, go left and get the Dragon Coin, then take the key. Get in the water on the left, then go down and swim right, past the Cheep Cheeps, to put the key into the keyhole. The path to the east will unlock and you can go to the Red Switch Palace.
If you don't want to go to the secret exit, then after you use the P Switch, just go back to the right. If there is still a big pit of coins, you can optionally get them, then wait for the P Switch timer to run out, or jump off a Buzzy Beetle, or if you made a hole in the floor, go through it.
From the water underneath the pit of coins, go to the right, then swim up and out of the hole where there is a Prize Block or Brown Block. (The bottom-right path doesn't lead to power-ups or coins or anything.) Jump up and onto the ledge on the right, then run up the slope, but beware of the Lookout Chuck at the top who breaks through the wall of Blocks. Let it run past and jump over it.
After that, there is a Buzzy Beetle, then the Midway Gate, then another Lookout Chuck that charges through the wall. Get past it and hit the Roulette Block to get a power-up. Then hit the Buzzy Beetle after that, and press down to slide down the slope and get the Dragon Coin. Then step on the P Switch and collect the wall of coins.
There is a Lookout Chuck after that, and a Prize Block that contains a Fire Flower. To the right, there are three coins, and a Buzzy Beetle on the ground below. Go past the pipe to get the four coins and Dragon Coin above the Buzzy Beetle, but go back to the pipe and go down to reach an icy cave.
You will slip on the icy floor, so be careful. Go to the right, past the two Buzzy Beetles, then get the coins above the water that has a Cheep Cheep in it. Get the coins over the next gap, then get rid of the two Buzzy Beetles on the platform, then jump and repeatedly hit the Prize Block as quickly as you can to get as many coins out of it as possible before it turns into a Brown Block.
Then go to the right, onto the platform with the Spike Top, and get the coins on the right. Then go up the pipe. Beware of the Swoopers that swoop down at you as soon as you come out of the pipe.
Go to the right, past more Swoopers, but don't hit the Prize Block yet. First, defeat the Splittin' Chuck that splits into three. When they're gone, repeatedly hit the Prize Block as quickly as you can to get as many coins out of it as possible before it turns into a Brown Block.
Then go to the right, past the platform with the Spike Top, and go through the Giant Gate to complete the level.
After the Level
If you went through the secret exit, the path to the east will unlock and you can go to the Red Switch Palace. If you went through the normal exit, the path to the north will unlock and you can go to Vanilla Ghost House.