Super Mario Bros 2j (aka The Lost Levels) was originally released on the Famicom Disk System (FDS), and was never given an official cartridge conversion. Even the Virtual Console re-releases are running off of a modified FDS BIOS. This can cause some issues when trying to load the game on some emulators, Everdrives, or the NES/SNES Classic Minis. So, a while ago, an NES conversion was made titled "Super Mario Bros 2 (Unl)" or "Super Mario Bros 2 (J) [p1]". This converted the FDS game to NES, but with a few catches.
1. Most evident, the title screen graphics are missing.
2. The final room where you rescue Peach is corrupt, so the player cannot progress to World 9.
3. There is no save data, so turning the system off prevents your progress from unlocking worlds A-D.
3.5. The combination of issues 2 & 3 make Worlds A-D completely inaccessible.
The patch below corrects the first of the 3 issues, restoring the title screen graphics to the rom. With this patch, you can freely play Worlds 1-8. If you die, your high score will show up on the title screen.
If anyone wants to tackle debugging the final room, it should make the cartridge fully playable.