Yay you figured out the coin clues :) The solution to the pipes is really simple once you know it, 5 steps total to retrieve the switch and move on. (Technically 6 counting leaving the room with the switch) It's easy to get confused though I admit, yet that was the point of that puzzle.
Did you notice each room's skeleton makes a unique sound when you jump on it, another way to map the maze.

I have a few easy ones.  Most of my levels contain secrets that make the level a little easier, and I've been trying to make them easier to find (especially in my latest one).  I know that the bomb part is difficult, so I put in something that makes it easier to do, as long as you think about it.  I try to make my courses as deliberate as possible. 

Yep that was another clever detail

Hey everyone, hope you're all making some awesome MM levels!

Just finished one of my own, in the spirit of Halloween!

It's based off The Haunted Mansion from Disneyland, as that ride is among my favorites out there!

Obviously those who have been on the ride will get more out of it, but I did try to make it fun and engaging for everyone, so enjoy!

The Haunted Mansion (200E-0000-00AF-8F66)

You make me feel good in all the right places Spurge. :D

ID: 0F3E-0000-00B3-B2F5

Did you know you can get a speed boost from jumping on enemies? Well did you know you can hover in goomba shoe while holding B? You did? Then give speed run level challenge a try! Aim for the gold (50 sec) but if your crazy, aim for the impossible time: 45 sec!

0F3E-0000-00B3-B2F5

Sorry, I thought copied the picture correctly with the code but I guess not.

So I went ahead and... uh... deleted my previous levels and updated them so they could be as perfect as possible!

Quick Update:

I want to thank Smeags for reorganizing the post with the shared levels. Now the user names are sorted in alphabetic order. He also suggested to put the name of the levels and since I like the way he adjusted the post I will start adding the names of the levels you share as well as the names of your old levels.

So if you want to help me you can post all the levels you have shared along with their respective name. Of course this is only optional, because this is something I should have done since the beginning so as a reminder to do thinks right I will be looking through all posts to search all your levels names. (I know you want to help with this as well smeags, but please don´t do it, this is something I have to do)

I made this level real quick.  Thought it was funny.  Titled "Take your time." Code is 2C2F-0000-00B7-EE9F