I was told to post this here.
Basically, GBHawk doesn't emulate the OoB in Wario Land 3 properly, or at least not in this level. Below are videos from different platforms showing how the OoB is supposed to behave for the purposes of a speedrun:
Gameboy Interface (Twitch clip)
Gameboy Player (Twitch clip)
3DS Virtual Console (Twitch clip)
BGB 1.5.8 (YouTube, timestamped)
I couldn't find a run on the speedrun.com leaderboard that was definitely on gambatte, so I recorded it myself. I do have more powerups than you would normally have in a speedrun, but that doesn't affect the OoB in this particular case.
gambatte-speedrun (YouTube, timestamped)
In the preceding videos, Wario falls down about 2 screens while hugging the left wall. Next, he heads right a bit before reaching the bottom of the screen for the third time and a jump is buffered by holding A. He lands on a 3 or 4 tile wide platform in OoB, but immediately jumps and is able to get hit by the Pneumo (the mosquito-thing that inflates Wario). Meanwhile, in GBHawk, this platform is missing, and other features of OoB are also incorrect (At the bottom, there should be blocks that Wario can dash into that will make unloaded tiles appear a deep blue. At the top of the RAM, there should be plenty of garbage; however, there is just a solid ceiling). I believe this is similar to or the same as how this OoB behaves in VBA, but I don't know for sure.
Anyway, here is an HD encode of a LOTAD that shows how the OoB doesn't behave properly in GBHawk (starting at around the 1-minute mark):
YouTube link
I wasn't anticipating that the first OoB section wouldn't work. I originally stumbled upon this problem because I wanted to test a new OoB room that only works on emulator, behaves slightly differently on 3DS, and crashes the game on original hardware. However, I cannot even get to that room because I have to be in this version of the level (daytime, without the blue snake door open), and in order to get to the correct section of the level without the blue snake door, this first bit of OoB has to be used. If I had to guess, even if I used cheat codes to move Wario into the proper in-bounds room and performed the setup to get into OoB there, that room would probably not be accessible in the first place.
Movie used for the above video:
User movie #73008826659546776
and here is console:
So something is wrong in between pressing start and game loading, I have no idea what, I don't think there are any sprites involved at this point. If I make GBHawk's VBL behaviour match Gambatte, then I do get the same screen as Gambatte, so it seems like there might be some new behaviour at play here.
