OK, I've had a few desyncs so I haven't finished the Prologue yet, but I aim to do so in the next few days. Though, I found something weird when I ran through the Goombella's Abilities tutorial on a certain frame:
Goomther the Goomba starts walking away, then turns around and exits the screen walking backwards! I have no idea why this happens. I get this result when I play my movie from power-on, so it's not a savestate issue. I'm planning to include this in my movie, since I have to wait for the moving platform in Rogueport Sewers anyway and I find this occurrence entertaining. I really wonder, though, why the game's programming allows this Goomba to do this on certain frames the cutscene starts on. If anyone has any idea why this occurs, I would appreciate you letting me know.
EDIT: I'm thinking this is an emulation glitch with 3.0-191. Professor Frankly did the same thing in Rogueport Sewers in my 191 movie, and I haven't been able to replicate either of these turning-around animations on 3.0-305.