Super Ninja Boy also works now. Found 11 instances of A9 04 8D 33 21 and replaced them with A9 00 8D 33 21.
What exactly is the issue with Super Ninja Boy? I know that it's an overscan issue, but to what degree?
I modified the 11 offsets in a hex editor just as you said, created SFROMs with both the non-edited ROM as well as the edited ROM, and synced them both onto my Classic. They appear to be identical after a quick playtest of about 15 or so minutes. Is the overscan issue a persistent one, or only on certain screens?
I've never played Super Ninja Boy before, so I'm not sure what the game screen is supposed to look like, but both non-edited and edited appear fine to me, everything fits on the screen and looks the same with both. Although again, this was only after about 15 minutes of playing, so maybe the issue occurs on certain screens? I'm not exactly sure what I'm supposed to be looking for to be honest.
Alright, I figured out where the overscan issue occurs, at least in the limited amount of playtesting I did. The intro sequence/splash screen, when you first boot up the game before pressing start, does not display completely accurately within the display window. It appears as if it's slightly positioned upwards, revealing a noticeable black bar at the bottom of the screen. It's fairly easy to notice since that intro sequence/splash screen uses a pinkish background which really contrasts with the black.
I haven't played too much of the game though, so I have no idea if there are other overscan issues throughout the game. Either way, Sluffy's fix definitely appears to work and correct the overscan issues, at least from what I'm seeing.
I would also just like to take the time to really thank Sluffy. He's truly amazing and his efforts are very much appreciated! Thank you Sluffy for all of your hard work!