I didn't know there was a hack of Kirby's Adventure out there! That's really cool! It looks like it's of good quality too, with plenty of differences from the original game.
As for your run, there are parts that can be improved. The easiest thing to fix would be delaying a frame or two before you reach Waddle Doos and Sparkies so they don't use their attacks (which both cause a lot of lag). Did you use FCEUX? If you did, you may not have noticed the game lagging because FCEUX's lag counter doesn't work well with this game. You can fix it with
this Lua script, which also gives you speed and position values in the corner to help you optimize the run.
Also, I love how the damage boost at around 0:53 in your encode gives you a speed increase for a few seconds. Is there a way to keep that momentum going longer? Maybe boost off of more enemies so you're moving that fast for most of the run?