Hey there. I think I found a bug but it could also be feature the way you look at it.
If you hold the Salty Runback command (L+R+A+B+Start) too long after the runback has already happened... the timer freezes and the game goes to Sudden Death. But depending if the stage is hacked or a skin, the game goes to the original stage. Like the City Dreamland skin goes to original Dreamland in Sudden Death. And WarioWare goes to Yoshi's Story 64.
Skip to 1:05 if you're impatient like me.
I know that Sudden Death is going to happen if the timer freezes like in the video there so I just try to beat up the CPU while waiting for glitch to happen.
Maybe this is just on my personal build/ISO?
(I changed the PAL files to Silly Melee and the SD Remix characters to 3.2.1 except for the unchanged characters. For the unchanged characters I made them PAL. And I have a custom banner and custom Game ID.)
Maybe it's a feature I never noticed? (like hitting A on the NTSC/PAL icon on the CSS sends you to the Rumble Screen.)
I'm not sure, but I think it's worth mentioning.
EDIT:
I guess it's just holding Start in general, because if you hold start while the stage is loading and during the beginning of that game, the timer will freeze and it will go to Sudden Death. And I think I know why now.
Holding Start like that will make the game think that time is up and will either go to Sudden Death or go to the results screen showing the winner. Now, I'm starting to think that this is actually a bug.
Edit 2:
evidence.mp4