I'm making this thread mostly to list all my level, since there is no webpage like in Super Mario Maker 1.
But if you want to play my level, feel free to do so.
Warning: I make varied levels. Some goods, some bad (on purpose), some may be kaizo.
Stars are my personnal opinion on how good the level is
meh
ok
good
great
From newest to oldest :

Chat-llenge! Mario vs Bowser!
J75-3K8-2JG
Made for a contest, it's just a short level with snake block and cat Bowser. Nothing interesting.

Banzaï! Cat!
MKC-J9P-TGG
Hard gimmicky level about cat Mario and Banzai Bills. Keep the banzai around.

The P-switch (eek!)
537-B4X-S0H
A level about p-switches, bombs, and a certain shape ;).

Small submerged forest
VVF-J52-BYF
Made quickly just to test the game, it's bad. How did it get 28 likes?

The ultimate puzzle!!!