Just a short level hack, only six levels long to be precise. In addition to altered level layouts, a few graphics have been changed or swapped around to make the game look a bit weirder.
A pretty straightforward ROM hack intended for commitment-free, short play sessions. Levels are more challenging than those in the original game, but fairness has been prioritized over difficulty.
Have fun!
Download and use the free program Lunar IPS to patch an unaltered ROM of Super Mario Bros.(NES)
That's all there is to it!
Database match: Super Mario Bros. (World)
Database: No-Intro: Nintendo Entertainment System (v. 20180803-121122)
File SHA-1: EA343F4E445A9050D4B4FBAC2C77D0693B1D0922
File CRC32: 3337EC46
ROM SHA-1: FACEE9C577A5262DBE33AC4930BB0B58C8C037F7
ROM CRC32: D445F698