The original Super Mario Bros. now has an unofficial level builder

digitaltrends.com:

Not only is there now an unofficial SNES version of Super Mario Bros. but the hacker behind it has built a way to edit levels in the game, a la Super Mario Maker.

As reported by Time Extension, Infidelity, a ROM hacker who’s been behind other NES to SNES ports, including one of the original Metroid, released the beta for both projects over the weekend on the Internet Archive. Super Mario Bros. Maker works on top of Infidelity’s SNES project, and is super easy to access. All you have to do is press X when you start a game, and then select one of the blocks that appear at the top of the screen. You can scroll through the options with your controller or an SNES mouse. Once you have the block you want selected, you can place it directly into the level. You can even save the changes or just reload the original level.

Say you want to add another question mark block to a part of a level where you could use a boost. The demonstration video that comes with Super Mario Bros. Maker shows the user adding it to the beginning of World 1-1, which can come in handy.

The project still needs some work. Infidelity noted in a follow-up post on Monday that it doesn’t work on many software emulators just yet, and MiSTer users are also out of luck. You also can’t do anything with enemies or sprites just yet, although that’s coming in a future beta release. There are also a lot of ways to get stuck or break the game, so check out the readme file in the download folder for all the current issues.

The readme also features some fun trivia about how the project came about. Infidelity wrote that he got the idea for it in 2019 or 2020 and originally thought of it as a hack for the NES, but didn’t really dig into the idea until this past July. “I was having success with the idea, was able to edit stages, but started to lose confidence in it since this was all theoretical, and this wouldn’t be universal on all hardware/software for the NES,” Infidelity writes.