Here is tutorial for potential russian speedrunners Created by Koh1fds in 2018 [RU]

WutFace Ok. I'm gonna explain what's going in this video. Warning! Most of this are assumptions, because i don't want to waste time on ram / debug research. But this is at least something.

So... It's possible to completely manipulate those flying things. Their trajectories depends on 2 factors:
1. Frame rule. I'm pretty sure you can find info about it somewhere in SMB1 community. I'm pretty sure this game (and actually Donkey Kong and Donkey Kong Jr) uses same frame rule mechanic as SMB1.
2. If flying thing goes bellow certain height then it somehow affects trajectories of other flying things.

So... At the next section i'm gonna describe how to completely recreate first 2 stages from WR run by Miha. So i'm not 100% sure if this is absolutely the fastest route or not. I'm just recreated his run.

So. First of all you have to start at correct frame rule. It's not that hard. I'm using sound cue for that. Just try to press start at the same part of the melody as Miha or i did.

How to understand that you started at proper frame rule? It's easy. You just have to watch how Olive throws first 4 hearths. If you pressed start somewhere close to the same part of the melody on title screen and if Olive trows 2 hearts to the right side of the bucket and then 2 hearts on the left side of the bucket then you are on proper frame rule. This is how first 4 trows should looks like:

So you are on the correct frame rule. What's next?
BIG ASSUMPTIONS WARNING!
Seems like If you never let hearts go below this red line then last 2 hearths are gonna fly at center of the screen and there is no way for you to pick them up as high as WR did. Obviously, higher you picked up last item in the stage => faster you beat it.

So this is how i pick up hearths to manipulate last two.
You have to let 3th, 4th, and 11 hearths to go bellow that red line. Every other hearth you have to pick up by top of Popeye's head or higher.

This how to pick up 3th hearh

You just go on the stairs and then go down by only holding down on d-pad! Then you wait until 3th hearth flies to you on itself.

This how to pick up 4th hearth

After you picked up 3th hearth immediately run to the left and stop just a little bit to the left of the those stairs.

This how to pick up 11th hearh

Same principle as 3th. Just go on stairs, then go down by only pressing down on d-pad and wait until 11th heart flies to you on itself.

After that you have to go up and pick up all hearths on the way. If you do everything correctly then last 2 hearths gonna fly to the left and you can pick up them like WR did. It also important to notice that it's very easy to lose frame rule on first stage. Seems like you are very very close to the next frame rule when catch those last hearths. And obviously if lose frame rule then that's it! Next stage can't be manipulated in the same way as in WR.

And here is how to manipulate music notes in the second stage,
First of all. Check if you still are on proper frame rule. It's easy! Just watch where 2 first notes flies. If first 2 notes flies to the left exactly as shown here then you are on proper frame rule:

It's actually quite easy to get last 2 notes in this stage to fly to the left so you can pick up them extremely high. Everything you have to do is to let second note to fall pretty low like this:
See how i picked it up somewhere in between those windows? That's it. Then you have to pick up all other notes at least by top of your head if you are on the lowest level. You can pick up them on the middle level no problem. If you do it correctly then Olive gonna trow last notes to the left again and you pick up them extremely high.

That's it! You manipulated first 2 stages. Hey! But what's about third stage? WutFace Sorry. I didn't looked into it. I just picked all letters as high as possible and there is no way to properly pick up last letter as wr if you do that. BUT! You notice how he let letter "H" to fall into the water: I'm pretty sure that's it! You have to do something like that and then last letter gonna fly in different direction. Ofc you still have to stay on proper frame rule after stage 2. Thanks for reading