These are only suggestions, you don't have to follow them.
General
- Change Offset: ~1.695
- combo colours should be the same in all diffs
- don't use the same slider velocity in all diffs, or is there any purpose?
aru's Kantan
- slider velocity is way to large for an easy map, something around 0,6 along with a distance snap of 0,8 - 1,0 should be better imo
- there are some parts with a circle at the ending point of an slider, this could be difficult for a beginner imo
00:28:575 (3,4) - this overlapping doesn't look so nice
01:06:506 (3,5,7) - maybe copy+paste and flip one slider looks better here
01:14:092 (6,7) - this overlapping doesn't look so nice
02:18:230 (1) - end spinner at 02:22:368
aru's Futsuu
- i would also suggest a smaller slider velocity with a larger distance snap
00:15:471 (4) - new combo
00:29:265 (1) - ^ ?
00:32:023 (1) - ^ ?
00:34:782 (1) - ^ ?
00:38:920 (1) - ^ (continues...)
00:51:334 (6) - ^
00:51:334 (6) - looks unsymmetric
01:18:920 (1) - end spinner at 01:21:678
01:34:782 (4,5) - overlapping doesn't look so nice
01:38:230 (1) - new combo
01:49:265 (1) - looks unsymmetric
02:18:230 (1) - end spinner at 02:22:368
Hard
00:06:506 (1) - delete combo?
00:12:023 (1) - ^
01:16:161 (4,5,6,7) - copy+paste one slider and flip it?
01:22:885 (1,2,3,4) - too much distance between the circles
Oni
00:35:471 (2) - looks unsymmetric
01:04:609 (2) - maybe move the 2nd waypoint 1 to the left
02:10:299 (5) - looks unsymmetric
02:13:058 (2) - ^
Star :3