Kirby's Adventure/Hidden switches

There are some doors on the world maps that can only be unlocked by activating some hidden switches scattered throughout the game. Some switches can be found easily, but most of them require solving a puzzle or possessing a special skill. There are 17 of them in all Below is the complete list of switches in the game. For each of them, how to find it and its effect is explained.

Note: You must complete this task in order to achieve 100% and unlock the Bonus Game.

Stage 3-1
When you enter the corridor with blue walls, descend in the second gap to find two star blocks. Remove them, revealing a hidden door. Go in, and you’ll be room with a bomb block, with a door on the other side of the ceiling. Dash into the bomb, blasting the ceiling. Enter the next door to find the switch.
 * Ability required: none
 * Unlocked: Arena

Stage 3-6
When you are climbing the clouds outside the tower, you will see a balcony with some star blocks on the right. Remove them to reveal a hidden door and enter. You’ll be in a room with a bomb block above. Hit it and quickly move to the right to reach the next door, before a wall that appears can prevent you. Enter to find the switch.
 * Ability required: none
 * Unlocked: Egg Catcher minigame

Stage 4-1
In the fourth area you’ll come to a cross-shaped group of blocks. You will certainly notice an anomaly, with an extra block. Remove that block, then go to that point and press, to enter a secret door and find the switch. If you have UFO, everything will be easier.
 * Ability required: none
 * Unlocked: Crane Fever minigame

Stage 4-3
In the windy part of the stage, with the airships, go to the bottom right of this area. Here you will find a blimp with a door. Go into the door to find the switch.
 * Ability required: none
 * Unlocked: Museum

Stage 4-6
In the pitch-black corridor, hop over a gap and proceed until you meet a Spook. Swallow it to get light and illuminate the room. Go back and jump back over the gap. You can now see a door to the left of a pillar. Enter to find the switch.
 * Ability required: Light
 * Unlocked: Warp Star Station

Stage 5-1
In the part of the stage where you must fall, evading the falling enemies, you will land on some star blocks, but instead going through the door, dig through the blocks and let you fall. You’ll land on other star blocks and you can spot a hidden door behind them very easily. Remove the blocks and enter the door to find the switch.
 * Ability required: none
 * Unlocked: Crane Fever minigame

Stage 5-4
In the first area with the waterfalls, you'll reach what looks like a conduit with water coming out of it, but it's actually a hidden door. Enter it to access a cave where you can find a Maxim Tomato and a 1-Up. There are two doors here - enter the lower one and you will find the switch.
 * Ability required: none
 * Unlocked: Arena

Stage 5-5
To reach this switch you have to solve a well thought out puzzle. In the first area, drop down into the first small gap to find a door. Enter and you will go to a field involving a Starman, a Hot Head, and a cannon. The cannon is blocked by star blocks. To remove them, inhale the Starman to acquire the Hi-Jump skill, then quickly clear the blockage. Drop the skill and inhale the Hot Head before it disappears from the screen to acquire the Fire skill. Light the fuse, then quickly hover and fall into the cannon, before it fires. You will land exactly on the switch. Note: if you don't manage to solve the puzzle, you can exit and try again.
 * Ability required: Hi-Jump, Fire
 * Unlocked: Quick Draw minigame

Stage 5-6
You must enter the level already in possession of the Hammer skill to find this switch (the quickest way to obtain this ability is to challenge Bonkers in the Arena of this world). This is one of the toughest switches to get. Then, you have to go through almost the whole level without losing the Hammer. Easier said than done. In the last area of the stage, there is a door on a palm tree. Upon entering it, you will enter a flooded room. There is a hidden door behind the star blocks in the middle. To reach it, you have to destroy the top two green bricks and the only way to do that is to use the Hammer. Inside, you'll find the switch.
 * Ability required: Hammer
 * Unlocked: Warp Star Station

Stage 6-1
In the middle of the second area, there is a door which leads to a small cave. Inside the cave, there is a secret door underneath, but it is sealed off by a white brick. The only skills that can destroy this brick are Hammer and Stone. If you already have one of them, just use it. Otherwise, you have to inhale two enemies with special skill at once (there are many of them outside the cave) to get Mix and hope to get one of the mentioned skills. After destroying the brick, enter the door below to find the switch.
 * Ability required: Hammer or Stone
 * Unlocked: Museum

Stage 6-2
The best way to reach this switch is with the Stone skill. You can get it by entering a hidden door right above the Pep Drink. Then, in the area with clouds, reach the door in the middle. A Bomber in this area may hurt you, so use your skill to become invulnerable. Enter the door, smash the pole in the middle and enter the lower door to find the switch. Alternatively, you can enter the level with the Hammer skill and use it to smash the pole, but don’t lose this skill along the way is not easy.
 * Ability required: Stone or Hammer
 * Unlocked: Arena

Stage 6-3
The process to reach this switch is really long and intricate. After defeating Bonkers, acquire his Hammer. Climb the ladder and use the hammer to break the box on the right. Proceed to the right and go down. Go left and smash the bomb block along the way. Then position yourself where the bomb block was and push to enter a hidden door. Defeat the Sword Knight and go through the hidden door behind him (it seems closed but it’s not). Get the Laser skill from the Laser Ball before it flies away and then go back through the hidden door in the water. This time go through the door on the left. Ignore the Hot Head (leave him die in water) and use Laser on the slant on the right wall, to light the fuse. Quickly jump into the cannon before it fires and you’ll finally reach the switch.
 * Ability required: Hammer and Laser
 * Unlocked: Crane Fever minigame

Stage 6-4
In the second area, once you reach the bottom right corner, before going up the ladders, enter the water below them and go to the bottom of the small recess on the left. Press to enter a secret entrance and find the switch. This was really well hidden.
 * Ability required: none
 * Unlocked: Egg Catcher minigame

Stage 6-5
The best way to reach this switch is to enter the level already in possession of the Fireball skill. (you can aquire it from Fire Lion in the Arena of this world) and keep it until the last area. Easier said than done. Anyway, in the area with the grey ground, there are two bomb blocks to detonate: the first one The first clears the path for the fuse and the second allows you to reach the cannon. After doing this, light the fuse with Fireball, than quickly fly out of this cavity avoiding enemies and use the same skill to quickly move to the right, simultaneously killing any enemies. In this way, you should reach the cannon before it fires. Enter the cannon to reach the switch. Alternatively, you can acquire Fire from the Hot Head you find on the spot, but with this skill, reaching the cannon before it fires, is likely to be too complicated and frustrating.
 * Ability required: Fireball or Fire
 * Unlocked: Quick Draw minigame

Stage 6-6
In the first area, right before the Sword Knight, drop down and fly to the left. Here you will find a door after a precipice, but it’s blocked by two ice blocks. There are two ways to remove these ice blocks. The first is to use Fireball (you can aquire it previously from Fire Lion in the Arena of this world). The second is to move to the next area of this level and acquire the UFO skill from one of the enemy you can find here, than turn back. The most powerful attack of the spaceship can destroy the ice blocks. Enter the door behind the blocks to find the switch.
 * Ability required: Fireball or UFO
 * Unlocked: Warp Star Station

Stage 7-1
In the second area, some of the blue blocks that border the path are actually destructible. In the point where you meet a Flamer, you can open your way through the floor using a skill or a slide attack and then proceed to the left. You’ll meet a Waddle Doo, acquire the Beam skill from it. Then proceed along the normal path, until you see three Waddle Dees trapped by blocks. Above them is a hidden vertical path that you must reveal with the Beam, destroying the blue block. In this way you can approach to the top door. However, the last two blue blocks before the door cannot be destroyed by Beam. You have to go back and inhale the Flamer you saw before, to acquire the Fireball skill. With this skill, you can destroy the last blocks and reach the door that leads to the switch.
 * Ability required: Beam and Fireball
 * Unlocked: Crane Fever minigame

Stage 7-6
Easy to reach, but very well hidden. At the end of the level, where the exit door is, fly exactly under the moon and press. You will enter a secret room with the last switch.
 * Ability required: none
 * Unlocked: Warp Star Station