How to clear Star World 5 in Super Mario World for the Super Nintendo Entertainment System and Game Boy Advance.

How to Reach Star World 5
Star World 5 can be reached by finding the secret exit in Valley of Bowser 4, or by finding the secret exit in Star World 4.
How to Clear Star World 5
If you want to reach the secret exit in this level, but you haven't visited the Yellow Switch Palace, the Green Switch Palace, the Red Switch Palace, and the Blue Switch Palace, you can go to Star World 2 if you have unlocked it, and get a Blue Yoshi there, then use the normal exit in that level so you keep Yoshi with you.
There are several Flimsy Lifts, which fall after you have stood on them for a moment, with green Koopa Paratroopas above them. Then there are several more Flimsy Lifts, this time with red Koopa Paratroopas above them.
After that, there is a Mushroom Platform with a P Switch on some Blocks, and a Prize Block. When you hit the Prize Block, you need to immediately push right on the controller so the snake of coins will move to the right, then stand still to make sure it continues to go to the right. Wait for the coin snake music to end (about 25 seconds), then step on the P Switch and run to the right along the Brown Blocks. Carefully get past the green Koopa Paratroopas and red Koopa Paratroopas along the way. At the end, if you want to visit the Secret Exit, and if you have visited all four Switch Palaces, quickly hit the third Block in the row of four Blocks to make a Beanstalk appear. Climb up it to reach an area of Yellow Blocks. Go to the right and you will go across some Green Blocks (but you will have to run and crouch to slide under some Gray Blocks if you're tall), then some Red Blocks, and finally some Blue Blocks. At the end, jump onto the ledge so you can get the key and use it in the keyhole.
If you want to go to the Secret Exit but you haven't visited all the Switch Palaces, but you have a Blue Yoshi, there is a way to reach the Secret Exit later.
For now, go to the right on the Flimsy Lifts after the four Blocks, past three red Koopa Paratroopas, and you find a Yoshi Egg. It will hatch into a Yellow Mini-Yoshi when you get close to it. If you feed the Mini-Yoshi five objects, such as enemies, coins, Grab Blocks, or if you feed it one power-up, it will grow into an adult Yellow Yoshi. If Yellow Yoshi has any color of shell in its mouth, it will make the ground shake whenever it lands, and will create dust clouds to the left and right. The dust clouds can defeat nearby enemies. This effect lasts until you spit out the shell or until Yoshi swallows the shell.
Go to the right, where there are three Spinies and two Jumping Piranha Plants. After that, there are four Flimsy Lifts. Jump to the right from the fourth Flimsy Lift to reach the Mushroom Platform on the right.
If you have Blue Yoshi and want to go to the Secret Exit, have Blue Yoshi eat the red Koopa Troopa, then go left, past the green pipe, and fly up to reach the room that has the key and keyhole. Have Yoshi eat the key and walk in front of the keyhole to activate it.
Otherwise, if you don't have Blue Yoshi or don't want to go to the Secret Exit, just get past the red Koopa Troopa and two Spinies, then jump up to the next Mushroom Platform and get rid of this red Koopa Troopa and the three Spinies after it, then go through the Giant Gate on the right to complete the level.
After the Level
If you went through the normal exit, you will go back to the Star Road entrance nearby. If you went through the secret exit, a path opens to the north, leading to a Star Road exit that goes to the first Special World level, Gnarly. This also gives you access to Star World 1.