General
Colours are nice, but the blue is too dark and blends into the background too much. Make the blue brighter.
The music is loud. Tone it down.
You need to incorperate some hit sounds. For example, on 00:28:53 (7,8,9) in Hard you can have Clap-Clap-Finish.
Easy
Rename to Easy.
Decrease HP drain rate.
You didn't retime this. Should I?
Try a slider tick rate of 2 instead of 4.
01:11:34 (1) - End at 01:12:81.
01:17:72 (1) - Move 1/2 forward to 01:17:92 (1).
01:18:75 (2) - Move 1/2 forward to 01:18:94 (3).
01:23:02 (1) - Move closer to 01:22:00 (2).
01:25:64 (2,3,4,5) - New combos for each.
Hard
Rename to Hard.
00:30:58 (13) - Weird slider. Retime it and add a new combo.
00:37:36 (3) - Unstack.
00:54:89 (1) - This is crooked.
01:05:12 (1,1,1) - Unstack these.
01:10:24 (1) - This is crooked.
01:20:85 (1,1,1,1,1,1,1,1) - Delete these. Only one is good. Replace with a break.
01:40:68 (1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1) - Ew. Make a nice pattern with this.
01:53:47 (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15) - Beautiful, and creative. <3
02:08:57 (8) - New combo.
02:12:66 (5) - New combo.
02:13:94 (6) - New combo.
02:19:06 (2) - New combo.
02:26:48 (1,1,1,1,1,1) - Same comment as before.