skin:
1.I think the combobursts can be larger, 600~650 high is better.
2.the shape of spinner-approachcircle is too sharp imo, you can use some lighter color instead of red to make it look more smooth. The same problem exists at spinner-circle but not so serious.

storyboard:
disable the "Letterbox during breaks"?

collab:
00:08:444(4,5) not straight and a bit weird imo. I don't know if you do these on purpose.
00:12:716(3) ^
00:46:896(7) ^
00:47:639(1,2) move this part so that stack with 0045781(6,7) or at least at the same X point.
00:49:310(2) same as 0008444(4,5).
00:55:998(5) stack perfectly?
01:03:242(5) ^
01:06:029(4) try to make this stack with 0104728(3)? or at least make them at the same Y or X point.
01:15:502(2) stack perfectly?
01:16:245(2) ^
01:27:762(x) start to put notes here?
01:32:221(3) make the middle point 1 grid down and right, then make the end point at the middle of the end circle. just like this:

01:32:964(5) delete this and flip the previews 3 if you remade it.
01:38:908(5) end point 1 grid right
01:51:168(4) same as 0008444(4,5).
01:51:725(2) ^ and stack perfectly?
01:52:097(3) stack perfectly?
01:55:812(6,7,1) move this part so that 1 can stack with 0155069(3)?
02:16:060(9,1) same as 0008444(4,5).
02:20:146~02:21:261(x) add notes at the 4 white ticks?
02:39:094(1,3) make them at the same Y point with the previews 7? I mean a straight line.
02:39:279(2) stack with the start circle of 0238165(2), or at least at the same X point.
02:40:208(2) same as 0008444(4,5). and what's more I think you'd better stack the end circle with 0239094(1), or at least make them at the same X point.
02:40:951(5) same as 0008444(4,5).
02:44:109(3) why not stack with 0242809(2)?
02:45:224(2,4,6,8) why not stack with the start circle of 0244109(3)? btw, these notes themselves are not perfectly stack, though 8 is perfectly stack with 6.
03:01:385(1) this slider looks weird, try to make it a perfect arc.
03:01:385(1,2,3,4,5,6) why not just make this pattern a bit up so that 4 will be at the center and stack with 03:04:357(1)?
03:04:357~03:05:843 a sec can not be a break...it will be better to delete it imo. add a note at the middle of this break then delete the note, the the break will disappear.
03:09:558(4) I really think a perfect arc shape is better here.
03:20:889(2) same as 0008444(4,5).
03:22:190(3) why not stack perfectly with the end circle of 0321261(1)?
03:24:790(2) same as 0008444(4,5).
03:30:363(2) stack perfectly?
03:31:106(1) ^
03:32:964(1) ^
03:34:264(x) add a note here and start the spinner at 0334357?