@mitu Ah I see! That makes a lot of sense. I've got it now thanks! Just need to figure out what buttons I've got and it's all dandy. Although I guess I also need to map some of them so I can still exit retroarch.
@Katzenfutter To be fair, I just played that first scene a few times on my end and no significant slowdown on the Pi3 nor the Pi4. I am convinced at this stage that i might either be an options thing (do send them over) or just your memory tricking us in that that same slowdown probably occurred on the real hardware.
@dankcushions Okay cool, thanks! For the bit of time I tried without the speed hack it seemed to run smoothly but I'll turn on the FPS counter to confirm. So the speed hack does exactly what it says, speeds it up, I guess it was self-explanatory after all.
Unfortunately, there have always been emulation issues regarding this game. Before 2004 it was completely unplayable on any emulator past the abandoned factory. It might help to raise this issue over at the libretro forums, as they're more likely to have insight into the nuts and bolts of this.