Just unlocked all the Mystery Mushroom costumes, which means I won't have to suffer from those unfair death traps in 100 Mario challenge anymore. My Wii U Pro controller sure has suffered from being thrown at the ground... (and its sticks broke, ugh)
And since I had two courses to post but I needed some specific costumes to publish them, here they are:
Aether & Dark Aether (MP2) (0E1A-0000-00BC-2E1D)
You discovered a new planet... a planet destroyed by its dark twin, which will be mandatory to explore to progress in spite of its dangerous atmosphere. Then you'll have to penetrate the fortress of the space pirates, and find Luminoth technology that will allow you to go back in Dark Aether without being damaged by its atmosphere, where the vital energy of the planet Aether had been stolen!
I already posted a version of this stage earlier, but I edited it to improve the level design. I also wanted to unlock the ZSS costume because you know, the endings of Metroid which reveal the woman being the suit.
Edit: updated version to make sure you can't break the part with the piranha plants.
Edit 2: fixed yet another game breaking way at the top of the pirate fortress by adding two hidden blocks.
Edit 3: YET another fix... just realized you could simply fly over the pirate fortress, so I fixed that.
Super Smash Maker (7D92-0000-00B7-2877)
My favorite level so far, one I polished a lot and wanted to publish after unlocking all the Smash costumes, which I just did. In this level, you'll need to keep a Smash character costume to progress; if you take a hit, you'll need to go back in the room with all the costumes and take another, though I designed this level to make sure coming back to this room isn't too tedious. I even put a system of doors and bricks to make sure you can easily skip a part of the level if you already beaten it.
In this level, you'll probably recognize the Smash symbol, the Battlefield stage as well as Final Destination, and the three Assist Trophies on these stages (Hammer Bro, Chain Chomp and Lakitu). The second and third part of the level are loosely based on the Master Fortress, too. I put a lot of work and testing in this level, so I hope you'll enjoy it!