[PowerPanda]

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.

Download: https://drive.google.com/file/d/1SlsJpxbt-Rd2HHMZPxpgz8fS7V894cqH/view?usp=sharing

[Green Jerry]

In the Kaiser pirate, the title screen looks like this:

The ROM size of this version is 128 KB.

The version without the title logo is called "Super Mario Bros 2 (Lost Levels) (Unl)" and its ROM size is 72 KB. Are you referring to this one or to the Kaiser one with a changed logo?

[RealGaea]

I used the 72KB version. Logo is restored, but blocks access to selecting a stage (I could do that using A and B).

And I think Peach graphics are glitched.

[PowerPanda]

Interesting. It seems there are multiple versions out there. The one that I use is named "Super Mario Bros 2 (J) [p1]", which I believe is the same as "Super Mario Bros 2 (Lost Levels) (Unl)". It is 73kb. I will update the original post. And yes, Peach's graphics are glitched. You only ever get the doorway because there is something that happens when switching from the doorway to Peach's screen. That's the part I haven't tackled yet.

[TRIFORCE89]

My go-to has been the loopy port with some GameGenie codes documented elsewhere that unlock all the levels on a playthrough without having to replay it multiple times.

I turned those codes into an IPS patch before but RHDN wouldn't accept a patch on this port when I tried to submit.

[PowerPanda]

Thanks for letting me know about Loopy's patch. It looks like my job is done. I haven't found a working link to Loopy's MMC3 patch, but I did find one on the last link of this reddit thread that has the game fixed.

https://www.reddit.com/r/Roms/comments/dd20xq/question_about_smb_lost_levels_nes_rom/

EDIT: I found the Loopy rom, and it has the same hash as the one in that thread. Here is a link to the source code for it.
http://3dscapture.com/NES/

As a bonus, the 8th post in this thread gives you hex values to edit to have Worlds A-D always unlocked:
https://www.famicomworld.com/forum/index.php?topic=11006.0