Here am I, with another rare bug. I tested a lot because I noticed it in my hack and it happens in origianl Sonic 1 game too (in REV00 and REV01). The bug appears in Labyrinth Zone, when you are out of water, sometimes, for a frame (not noticeable too much if you don't see the game frame by frame), the entire screen show the underwater palette...
Here is an screenshot to show what I mean:
As you can see, here, at the middle of the screen is the water surface, but the entire screen is with underwater palette. As I said, this only happens for a frame, and then back to normal, but it's repeated more times.
Anyone noticed this? is there any possible fix? what is causing that?