I've played this game more times than I really think that I should have needed to, and after all these years I think that I can safely say that it's not a bad game, or at least it's not as bad of a game as I initially pegged it to be.

My history with this game is pretty bumpy. I had a very bad first experience with the game and wrote it off as being an unfair slog full of beginner's traps and a laundry list of awful game design decisions. I held this opinion for over a decade without having played more than the first world or so of this game due to the peculiar nature of its secret reward scheme and recalling absolutely miserable memories of trying to beat it over the course of an entire summer vacation in high school. It wasn't until a friend of mine talked about it in a few discussions late last year that I started thinking past my bad memories of it and possibly psyching myself up to try it again.

The benefit to this being on the Famicom Disk System instead of the original NROM Famicom cartridge format is that there's slightly more room for things that I don't think there was space for on the cartridge, in addition to some overall tweaks to the physics to both serve as foundation for things that would become staples of the series, and to differentiate the Mario Brothers from each other beyond their palettes, as had been the case with their prior two Famicom outings.

And I suppose that I should start on that last bit: I think that maybe the problem that I've had with this game all this time is that I've been playing as his older brother. After having run this game close to four or five times now, I can confidently say that I feel like this game was made with Luigi in mind: it's simply more fun to play as him than it is to play as Mario. Luigi's slippery acceleration makes potential mistakes that would be easily salvageable as Mario into do or die situations and it's simply exhilarating to just BLAST through levels as him, utilizing his jump momentum and the enemy bounce to pull off things that I would never have imagined as being possible for a regular player to do before.

As for the difficulty... yeah, it's not great, but it's also not the hellscape that I've heard it described as or even described by myself in the past. I know, for instance, that a lot of people like to mention that the Poison Mushroom in 1-1 is a beginner's trap, but the attract mode telegraphs what it does pretty well (it's the thing that kills Mario, even) and it doesn't take very long for said demo to start up from the title screen, so it's really only a beginner's trap if you're impatient and just press the start button the minute that the game loads, which you should never do with older games like this. Poison Mushrooms as a whole really aren't that much of a problem, though. They usually aren't placed in overly dickish locations, they're not all that difficult to avoid, and they're seemingly far outnumbered by regular Mushrooms and Flowers. In fact, the thing that'll probably kill you more often than not is not being used to the finnicky and overprecise jank that is Super Mario Bros. 1's physics system and how air control works, but that's more of a problem with the fact that this game is built off of the first game than really an inherent problem of the game in and of itself. In fact, there are even sections in the secret worlds A through D and a handful of tiny moments in the main game where I could almost swear that they were testing out concepts to be used for Super Mario Bros. 3, such as Koopa shell rebounds and how they react to certain structures.

With all that out of the way, let me gush about the aesthetic a bit, because this game is absolutely stunning with the way that it's presented. A lot of the tiling issues in the first game have been dealt with here: the ground looks more like it's made up of gravel or rounded pebbles rather than a bunch of the same distinct block, the bricks all have definition and no longer have that strip along the top that makes them obvious on the castle wall backdrops, the familiar eyes that dot the landscapes make their appearance here, and a lot of tiles in general just get a bit more oomph to them to set it apart.
Additionally clever usage of palettes and new enemy/object introductions throughout the game also seem to tell the story of a subtle passage of time over the course of the adventure: you start the game late spring, and you hit summer by about World 5, where the Piranha Plants all ripen and turn red for the rest of the game, and the wind starts blowing really hard. Then, by the time you get to World 8, summer's finally started turning to autumn, and all the trees and bushes in the background are turning colors and getting ready to drop their leaves. (I know that it's just because World 8 primarily uses the Mushroom Forest palette and that turns all the trees and pipes orange, but let me have my delusion.)

Overall, this game has a lot of charm to it, and it does a lot of things that I adore: it intrigues me, it jumpstarts my imagination, it gives me a feeling of exhilaration that I haven't felt from many other games. But on the other hand, it's basically just more of the first Super Mario Bros. and I kinda don't like the first Super Mario Bros. very much. It also doesn't take a whole lot of advantage of the medium that it's on, I think it only uses the extra space to add the new things and a disk system rendition of the full ending theme that was in Vs. Super Mario Bros. for the arcades, and that's disappointing to me because after the showcase for the disk system that was The Legend of Zelda, this isn't as impressive. So while I had a better time this go around than I think I've ever had with it before, I can't really rank it higher. Give it a shot and go in with an open mind, but don't expect greatness.