Response to my judgings
The main reason that there were so many different themes and glitches was that Bowser was throwing everything that he had at you, no matter the mess it made of his castle and lives lost. And the main inconsistency comes from this.
When making a castle, I always kind of wonder how to decorate it the right way. It's a castle, so most plants wouldn't work, and why would there be amazing decor in a castle where everything is being thrown at you for your death? And especially Bowser, as most of any decoration he has is cannons in the shape of his face and maybe a rug then and there.
Well, that butterfly wasn't the only hint to the hidden pipe. If you looked at the checkered pattern of the flooring, you'd notice that the tile that the pipe is on isn't checkered like the rest of the floor.
NOTE: I'm not trying to say "Your judgings aren't accurate! I should have won first!" I'm just saying what I want to say to my judgings. Congrats to the winners and those who participated!