Hi! I'm Dan. I post on Metafilter as branduno, and my girlfriend and I post levels on Mario Maker as Michelle. My ability to play is sporadic, but I'd like to drop in here at least once a week.
My latest level:
Kuribo's YOU: 112E-0000-0092-EC90
I love Goomba's shoe, and I love Goombas, and I love turning into a Goomba. I loaded it with Mystery Mushrooms to minimize the chance that you'd have to go through the level as anything but a Goomba, and shoes to minimize the chance that you'd have to go through barefoot, but it's pretty simple to complete it with neither (and without going into the hidden areas).
Older levels you may have seen since I already posted a couple on Metafilter:
Fish In The Trees: 18AB-0000-0072-D755
This started when I was trying to recreate the falling Cheep-Cheep levels like 2-3, and then I just liked how the fish flop around at the bottom. John pointed out riding the Lakitu cloud makes things quite easy, which I always feel is an adequate trade-off for getting to ride a Lakitu cloud.
Koopa Canyon: 8A34-0000-0072-A16C
Short and simple; I just like bouncing off Koopas; I intended the challenge to be less getting to the goal and more making it up to the higher platforms.
Shipping Schedule: 21B1-0000-006E-692E
A Mario 3 airship level that I think I tried to be a little too clever with. It's not difficult difficult, but finding the exit is a little more obtuse than I think I intended.
Bowser Schmowser: 0737-0000-005A-10A7
Bowser & Son try to impede your progress through a Mario World level filled with capes and P-switches!
Go Fish: D542-0000-0059-B66F
There's a lot of fish in this level, but fire flowers and a star make them fun to plow through. I like how the underwater style lends itself to nooks and grottos to explore.