Welp, that was surely pretty cool to say the least.
Although I'll admit there were faults, such as Balrog's occasional (actually more than occasional) jumping through the walls (although I guess that's not your fault, as it is Sonikku's sprite, isn't it? If his jumping through the walls is the result of catching the wall (in a similar way TASers could make Mario wall jump, then wouldn't applying this
patch make it so Balrog no longer walked through walls?)).
And then their were the awkward vanilla cave sections interrupting Kirby styled places and everything (which had little to no purpose, but do derail the original theme, and the random castle segments in normal grassland levels. I'd suggest either taking the castle ideas you had for those things and just formatting them into full levels, so you have levels with a steady theme instead of captain all-over-the-place.
Also I guess the format of the game was kind of annoying to me. Like it's sole purpose was to just exist. There wasn't any outdoor music happening at Peach's Castle which was awkward, I never had to use the shop once the whole time with the excess of items (oh and the vanilla blank level which you could enter the shop was kind of lazy, in my opinion)
Also I understand you were trying to create a brutal mario-type game with the graphics all over the place, but usually you'd like to keep a certain style. Some people can pull it off, but unfortunately for you that wasn't the case (although that might be because none of the levels flowed with each other, so it didn't feel like a solid experience.)
so the format reminded me kind of like the cheap demo or whatever, from carol, where it was a dozen or so levels that were each unique to themselves and introduced some new gimmick. However with what you're using, all your resources in terms of sprites and general gimmicks were created by other users and are free to use here, so they are no longer 'uniquee'. Plus a few of your levels had secret exits that just led you backwards.
I guess my suggestion would be that if you ever intended to do something else with this or whatever, to maybe establish a more base-type game (themed worlds to a degree, instead of everything crammed into one smaller submap)
Anyway that's what I think. I hope that was good enough constructive criticism.;