I'm sure this has been dealt with before, but I wanted to throw my 2 cents in.
Episode 6, Floor 10 (Secret) has a unsolvable push-wall puzzle. It is located in the lower-right quadrant of the level. I took some time and unraveled the puzzle to see how it could be solved. I have determined that, unless you have reinstated noclipping, you won't solve this puzzle. I created two images of the area in question, and labeled the push-walls according to the order in which they should be pushed. Note that 3 and 4 are interchangeable, meaning that you can push either one first and the result will be the same. The second image shows where the walls should end up after being pushed.
The problem comes in with push-walls 6-13. In order to push all of the walls and get 100% completion on the secret aspect of the level, you must push wall 6 first (after 1-5 have been pushed). Looking closely at the images, you can't push wall 6 in the direction necessary because you can't get to that side of the wall without using noclipping mode to get there.
It is possible to push wall 6 in the opposite direction, if you push wall 10 in the opposite direction of that noted, but you will block walls 7 and 8, preventing them from being pushed at all and rendering the puzzle incomplete and the total secret for the floor less than 100%.
Note that, if you push all the walls as indicted, you will be able to push wall 14 in either direction (left or right), and it won't prevent you from reaching the three free lives or from leaving the area once you are done there. This would enable you to achieve 100% secret for this floor, if you could reach wall 6 before pushing any other walls after wall 5. Because you can't do that, this maze puzzle remains unsolvable, again, unless you have reinstated noclipping mode in the game.
Due to the ghost being in the room that wall 5 blocks, getting those two free lives and getting everything else done in that little maze is next to impossible. I devised a method to get the free lives and block the door so that the red ghost cannot get out of the room. Once you enter that room, if the door is not blocked, the red ghost will follow you around, making it very difficult (and very dangerous) to try and unlock the maze. The method I have devised involves using God mode and noclipping. First, you push walls 1-5 so that part of the puzzle is completed. This blocks the door preventing the red ghost from escaping the room. Then, turn on God mode and noclipping. Walk through wall 5 and the door, where you will also pass through the red ghost who will hit you (the reason for God mode, so he won't do you any harm). Pick up the two free lives, then go back through the door and wall 5 until you are in open floor. Then turn God mode and noclipping back off. You have now gotten both of those free lives, and the red ghost is trapped in the room, unable to get out. You will hear him continually trying to get out, as the door to the room keeps opening and closing, but he cannot pass through the wall, so he is stuck there.
I realize that it may be difficult to tell which push-wall is which, so I made the following text-chart to assist with identification.
Episode 6, Floor 10 (Secret) has a unsolvable push-wall puzzle. It is located in the lower-right quadrant of the level. I took some time and unraveled the puzzle to see how it could be solved. I have determined that, unless you have reinstated noclipping, you won't solve this puzzle. I created two images of the area in question, and labeled the push-walls according to the order in which they should be pushed. Note that 3 and 4 are interchangeable, meaning that you can push either one first and the result will be the same. The second image shows where the walls should end up after being pushed.
The problem comes in with push-walls 6-13. In order to push all of the walls and get 100% completion on the secret aspect of the level, you must push wall 6 first (after 1-5 have been pushed). Looking closely at the images, you can't push wall 6 in the direction necessary because you can't get to that side of the wall without using noclipping mode to get there.
It is possible to push wall 6 in the opposite direction, if you push wall 10 in the opposite direction of that noted, but you will block walls 7 and 8, preventing them from being pushed at all and rendering the puzzle incomplete and the total secret for the floor less than 100%.
Note that, if you push all the walls as indicted, you will be able to push wall 14 in either direction (left or right), and it won't prevent you from reaching the three free lives or from leaving the area once you are done there. This would enable you to achieve 100% secret for this floor, if you could reach wall 6 before pushing any other walls after wall 5. Because you can't do that, this maze puzzle remains unsolvable, again, unless you have reinstated noclipping mode in the game.
Due to the ghost being in the room that wall 5 blocks, getting those two free lives and getting everything else done in that little maze is next to impossible. I devised a method to get the free lives and block the door so that the red ghost cannot get out of the room. Once you enter that room, if the door is not blocked, the red ghost will follow you around, making it very difficult (and very dangerous) to try and unlock the maze. The method I have devised involves using God mode and noclipping. First, you push walls 1-5 so that part of the puzzle is completed. This blocks the door preventing the red ghost from escaping the room. Then, turn on God mode and noclipping. Walk through wall 5 and the door, where you will also pass through the red ghost who will hit you (the reason for God mode, so he won't do you any harm). Pick up the two free lives, then go back through the door and wall 5 until you are in open floor. Then turn God mode and noclipping back off. You have now gotten both of those free lives, and the red ghost is trapped in the room, unable to get out. You will hear him continually trying to get out, as the door to the room keeps opening and closing, but he cannot pass through the wall, so he is stuck there.
I realize that it may be difficult to tell which push-wall is which, so I made the following text-chart to assist with identification.
- Code:
1 2 3 4 5 6 7
+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+
| | | | | | | | | | |x x x| |x x x|
| | | | | x | | x | | x x | | | | |
| x | | x x | | x x | | x x | | x | | | | x |
| | | | | | | x | | x x | | | | |
| | | | | | | | | | |x x x| |x x x|
+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+
8 9 10 11 12 13 14
+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+
|x x x| |x x x| |x x x| |x x x| |x x x| |x x x| | |
| | | | | | | x | | x | | x | | |
| x x | |x x x| |xx xx| |xx xx| |xx xx| |xxxxx| | |
| | | | | | | | | x | | x | | |
|x x x| |x x x| |x x x| |x x x| |x x x| |x x x| | |
+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+