current spectro: https://i.imgur.com/0NMFaXC.png
given that this is 192kbps, it's pretty clear that this mp3 is hella scuffed as it only peaks on 15.5KHz. here's a proper 192kbps mp3 that I converted from a high quality FLAC of the song: https://taco-user.s-ul.eu/V74elq5w
new spectro: https://i.imgur.com/KXthlGf.png - much better!
new offset is gonna be ~435. make sure to offset the video to sync with the music along with timing and svs, preview point, resnap kiais if unsnapped by checking AIMod/Mapset Verifier etc. you'll have to move everything by -1715
from now on all mods will be done with the new timing so keep this in mind
preview point and video still not fixed btw
you can fix the video by opening each .osu of all difficulties on notepad and changing the value under [Events] to -1715 as such: https://i.imgur.com/9Lz8ZxS.png
the beginning section is so inconsistent with each other difficulty that it's actually extremely confusing to understand what exactly are you following on each one of them. here's an example that stood out to me the most, but this also applies to the rest of the beginning section:
00:21:350 (25,26,27,28,29) - d d ddd on kantan, K K KKK on futsuu, d d ddK on muzu, all 2/1 and 1/1 rhythm. then on the oni you decide to map the 1/3 actively, which not only causes major issues with spread since the gap in this part is ABSURD, but also misrepresents the song by undermapping it on the lower difficulties when there's so much more that can be done, such as actually using the 1/3 on the futsuu, which is not a problem due to the song's low bpm of 125 and would allow for you to use 1/3 more liberally on the muzukashii - which would be a massive improvement over the current rhythm on nearly all difficulties.
aside from this, the major inconsistency between difficulties shows that even though you want to represent different sounds on each diff, your execution of it was sloppy with different patterns on every difficulty for the same rhythm, which creates confusion as to what you intend to follow in general.
you should revise this first section of the map and make them more consistent with each diff when it comes to patterning, while also building up on the rhythm instead of keeping it the same on every low diff and then mapping it on the top diff.
something that you didn't address was the major difference between the patterns themselves rather than rhythm across different difficulties, such as 00:21:350 (15,1,3,4,5) being Ks on the futsuu vs ds on the kantan
you could keep the d d ddd on the kantan and map the futsuu as dkdkddd, would be consistent with all diffs and would still keep the same rhythm you want to go with
also the entire point applies to later similar sections such as 01:55:430 which also have a massive difference between the futsuu and muzu and could have both a buff to futsuu and a nerf to the muzu applied to scale things better along with some other spread-related stuff I'll mention as I continue modding
meta check
Title: ドレミファロンド
Romanized Title: Do Re Mi Fa Rondo
Artist: 40mP
Romanized Artist: 40mP
while the song does feature Miku, the official uploads do not use feat./ft. Hatsune Miku at all (see: https://www.nicovideo.jp/watch/sm16719809 and https://www.youtube.com/watch?v=bphS6_wayug - the official uploads by 40mP), thus it shouldn't be used. aside from that, the romanized title should either be DO RE MI FA Rondo or Do Re Mi Fa Rondo as per either official upload - since both have different capitalization, you can follow either as the 2012 ranked set's metadata is incorrect
add "hatsune miku 初音ミク" to tags
I really recommend you to use the Taiko Video Resizer tool in order to have the video work properly with taiko's playarea instead of just being cut in half. Here's a link to it: https://osu.ppy.sh/community/forums/topics/1129583
Unicode artists should be "40mP feat. Hatsume Miku" according to the guideline of the standardization. And the "Artist" field should be modified accordingly.
could remove "40mp " from the tags since "40mp" is in the artist fields
btw you should add "j-pop" in my opinion
Current MP3 is really bad, use this mp3 and change the offset to 2150 .....
if od is 3 on kantan & 4 on futsuu, it would make more sense and make a clear 'gradient' (3, 4, 5, 6)