It didn't have to be like this.
Imagine if Super Mario Bros. didn't have rudimentary things like consistent controls, or side-scrolling, or even competent level design. That is what you'll be getting into with Super Mario Bros. Special. I could forgive the controls to some extent if the level design was forgiving to the player. For example, if the game never asked for very precise jumps onto small platforms, I might forgive it. But no, the game will make you take those jumps. It will also force you into situations where you basically have to lose a life due to a leap of faith going badly. There are also a few times where you'll have to make a jump and hope that an enemy doesn't fall on top of you immediately after the screen changes to the next part of the level. Classy level design.
We live in an age where there are ROM hacks of the original Super Mario Bros. - one of which is literally just SMB Special, but with the proper controls and side-scrolling that come with the original SMB. We also have Super Mario Maker games, so if you want to recreate the levels from this via SMM, go right ahead! Just making the levels will be more fun than actually playing SMB Special.