How do I get to the big red doors in the 8th level huge castle?

At the beginning of the castle, walk until you meet the second small path of orange blocks. Wait for the fireball in case you run into it. Repeat with the next path. Jump over the small stone wall, watching out for the fireball when you jump over the cliff. There will be 4 miniature cliffs with fireballs shooting from them at various times; so timing is very important. There will be another cliff with a fireball shooting from over it. After jumping over it and the next one, jump and go through the door. Break the middle brick and a "?" switch will appear. Jump on the switch, and the room will turn upside down. Go through the next door. There will be a flame that turns on and off. While off, jump over it. Now there's another one facing upward. For the next one, jump onto the tiny platform and duck until the next flame finishes its job. Jump on or over Dry Bones. Turn right and go past the two flames. It is very tricky so I'd recommend using the space where the flames can't reach. Next is a similar obstacle, but easier. Go through the door. Go past the giant thwomp and break the third brick. Another "?" block will appear. Jump on it to turn the room upside down, then go left, pass the thwomp, and go through the door. Go left and jump on Dry Bones. Make a jump up to the right and over the flame. To get to the next door, duck while running. Go through the next door. Go past the thwomps and down the hole past the spikes. Go left, and break the bricks until you find a "?" block. Jump on it to turn the room upside down. Go up to the left, and when you reach the ceiling go right. Jump over the spikes, and go through the door under the hole. Go through the door on the right and go up the steps. Go through the door. You are at the midway point. Go past the cliff with the fireball and up the platform past the next cliff. Go past the spike, and pass through on the 3 bottom platforms, and you will hear a sound effect. Jump over the 2 cliffs, and carefully go on the next. On the platform after that, jump over the small wall, and use the high platforms to hear a sound effect. For the next set of 3 platforms, slightly go on the bottom, then jump on the middle to hear a sound effect. Jump over the cliffs, go up the small wall, pass through the floating platform, up the next small wall, and go through the big red doors for the finnal battle!