"This is the Secret Level! Completing this level will give you a bonus you should find very useful!" - The Hint Block
The Pipe Passage is a short level in A Koopa's Revenge. It can be accessed by going through the secret pipe in Bowser's Castle 3. Along with the Training Level, it is optional. The level is filled with pipes and fireballs and has a sunset theme. If Koopa manages to pass through this level, he will gain access to the Power-Up Pipe.
Koopa comes from the pipe and hits a hint block that says, "This is the Secret Level! Completing this level will give you a bonus you should find very useful!". After, Koopa runs through a platform full of pipes with a few fireballs forming an obstacle. Koopa jumps up the sidewards pipe and goes down the lone pipe at the end.
Koopa passes through and lands on a small pipe. There is a fireball going in and out of a tiny sidewards pipe. Koopa must make his way and dodge the fireball. He then lands on an orange L-shaped platform with a pipe (which is also a shortcut that leads to the end of the level) below that has a coin above it. Koopa jumps and passes through a series of pipes and finds a row of ? blocks, one of them containing a power-up. In order to reach the next room, Koopa must jump left over a huge gap that leads to a lone pipe and enter the pipe.
In the last room, Koopa starts out on a pipe and needs to jump across to reach the flagpole. Koopa can now enter the Power-Up Pipe.