It's an unofficial fan made project, but oh my god it's the tits! You play SMB, but it's got all these quality of life improvements.
Like the background and clouds aren't static like they would be in the NES. There's options to backtrack. You can change the clock to unlimited, or change the seconds to real seconds. You can change how damage is done. American style, or Japanese style.
They included Super Mario Bros Special. Which is a rare 1986 Super Mario game, which was released by Hudson Soft. In the 1986 version the screens did not scroll with you. Instead you move forward, and the screen transitions. Well this game takes those levels, and lets you play them in the original SMB engine, with SMB graphics.
They included a mode from SMB DX where you had to hunt for 5 red coins, a yoshi egg, and get a certain score.
They included a boo race mode.
And Super Mario Bros 2 (Japan)
I don't even know what All Night Nippon Super Mario Bros is.
They included resource packs, which change the graphics. They have a stage builder. You can share or download others custom levels.
It has achievements.
Guys, this game is the real deal.
That's awesome. I'm definitely checking that out. Twists on SMB are one of my favorite things.
Mari0 is one that I sank a lot of time into in the late 2010s, but my all time favorite is Super Mario Bros. Crossover. It's SMB, but you can play through with basically every popular NES character with their original movesets. I'm talking using Simon's whip on goombas, spread shot taking out King Koopa as Bill Rizer. Hell, you can play through the game as Zelda II Link if you want.
That hyperlink may not be functional, as it's a flash game, but you can definitely find it on BlueArchive's Flashpoint Infinity. I recommend for all retro gaming fans.