Oh boy. So this is interesting. The first hack I made was called "Hi Mario World". The entire first world was full of automatic levels. One of them required you to press up to go into a door and fight Iggy. Iggy was slightly different. He was heavier, he spit fireballs, and the platform was slippery. Anyway, moving on, the real levels began in world 2. I had a habit of just copypasting stuff. Donut Plains 1 was just a bunch of volcano lotuses copy pasted, making a straightforward, repetitive, boring level. Then came a level where it was raining goombas, both normal and giant. I used sprite limits as a gimmick, saying that if the goal sphere is not present, you must defeat more enemies. Anyway, yadda yadda yada. Starting with world 4, things got kaizo. However, my level design seemed to improve when I was making more kaizoish levels, and I realized that I was better as a kaizo designer than a normal designer.
Oh, and should I remind you of how I was greybanned for 2 years because I kept submitting it over and over again without changing anything?
I still have the hack, and I use it to test out certain things. It's the only ROM I am able to test stuff on, because I have not made a proper hack yet. Therefore, you might see it constantly updated in my filebin, because I use it test gimmicks. It's also a hack that I can give youtubers who don't play proper hacks, making it a nice non-serious hack to give them.
Edit: For those of you who want to see it, here it is:
Hi Mario World
don't click this link...