[General]
The parts during the chorus when they sing "Where's my...", they beats always feel off because the singers take a moment to get up to full volume when singing the "wh-".
I'd suggest having a spinner at the end of each difficulty. As they stand now, they feel as if they just end suddenly.
[Easy]
The countdown sounds off from the drum beats.
With the hit sound pattern you're going (clap on 2, 4) I'd keep the clap off [1] at 00:31:450 and move it to [2] at 00:31:858.
00:36:960 Triple clap doesn't fit here.
01:14:304 [1] Add Whistle
01:15:121 [3] ^
01:15:937 ^
01:16:753 ^
01:17:569 ^
01:18:386 ^
01:19:202 ^
01:20:018 ^
01:25:732 The claps here don't fit the music at all. Try putting a whistle on 01:25:732, 01:26:344, and 01:26:548 instead.
01:28:997 ^ Follow the same pattern.
01:35:732 The way the singers delay the volume on the first note makes the start of this slider ambiguous, but where you have it now, the return bounce is off. The return needs to be on the white tick at 01:36:344. I suggest just making a non-return slider that ends on the white tick, then use a normal beat with a soft finish sound on 01:36:752.
01:46:955 [2] Maybe center this over the [1] slider?
01:50:220 [3] Point the end of this slider more towards the [4] or try to have a more gradual curve with the next two circles.
[Normal]
The hit sounds are rather different from the easy mode ones, and yet, they pretty much follow the same rhythm. Try to keep the hit sounds consistent if you're pretty much clicking the same stuff.
01:29:405 [7] This slider looks kinda weird.
02:04:505 [4, 5, 6] Remove whistle.
02:05:321 [7] Add whistle to beginning of slider.
Follow that rhythm with the whistles until 02:14:300, then continue again from 02:15:933 to 02:27:361.
[Hard]
00:14:308 [3, 1, 2] The way you progress these sliders is really unintuitive. A four hit, three hit, then four hit slider when the beat is steadily going on is kind of weird. I can see that they're changing to the vocal part, but that's not what I'm listening to when I'm doing steady 1/8th notes with the drums.
00:56:346 [11, 1] This jump doesn't feel like it should be one. It'd be better if you deleted 11, then did a jump.
01:10:835 [1, 2] Although these beats are in time with the music, it doesn't feel right with the syncopated vocals and bass for the sole accompaniment.
01:38:997 [9, 1] Same thing as 00:56:346.
SPOILERYou mentioned mod4mod while I was in the middle of this, so it's up to you if you want to mod back or not.