If you're going to have the Bullet Bills that emerge from the edge of the screen, please put in the Bullet Fire sound effect. It somewhat makes it easier and less cryptic to know when an oncoming Bullet Bill is present.
I know you said you no longer care about the difficulty, but please make sure it's real difficulty (in that the deaths/damages are from player error and carelessness) that's in the game rather than fake difficulty, which Mario Adventure 1 featured quite a lot of.
Owch, it's hard to hear criticism about your work, but I do agree, Mario Adventure 1 had a tendency to be difficult due to the game, not the player. I hope that my level design has vastly improved. I used to increase difficulty by increase the "chance" and "magnitude" factor. Random enemies and more enemies. There is none of that this time. Here's an example:
In this situation, you have 2 Koopas moving up/down and one moving left/right. If you fail one of your jumps, the bottom is solid, allowing you to climb back to the top and retry this specific area. It can be difficult, but any mistake here is due to your own timing.
There are several situations that may "surprise" a player but only on the first time the come across it. For example: a Cheep Cheep jumps from puddle to puddle. Then you come across a situation where there's only one puddle and the Cheep Cheep jumps out of it and starts to bounce on the floor. That may surprise the player the first time, but it's predictable and you can return to the area with new knowledge. Later on in the level you see the same scenario with slightly different parameters/level layouts. Granted, there won't be lives in this like in the last game, but dying will reduce EXP, so I'll have to be careful not to set up situations that cause people to die over and over again.
Anyways, thanks for the feedback about my old projects. I really do strive to learn from my past mistakes, and others', in order to bring a satisfying game to all SMB3 lovers. I do want to throw some "stupid hard" levels in the game, but, this will be something the expert players have to seek out, not something you're forced into.
When he did finish this hack, he will go back to work Mario vs Luigi?
I will not. Mario vs Luigi's data is long gone and picking the project back up would be near impossible for me.