Hello M4M! These are all suggestions feel free to ignore them if they didn't help.
GENERAL
- Palitan mo yung green color combo nito. Combo2 : 128,255,128
Easy
00:21:602 (2) - Don't you think it's too early for this kind of fast reverse for beginners? How about making it a 2 stacked note?
00:23:246 (4) - Looks better if put a little curve in it

00:26:945 (2,1) - Might be better if the new combo is on (2) instead of (1)
00:38:862 (1) - Add finish. Sounds better than the whistle.
00:42:927 - The clap doesn't seem to be very fitting here. Remove it please.
00:43:383 - Add a note with clap? This is much better, just adjust the following note's spacing and shape like this
http://osu-ppy-sh.tvgratuite.org/ss/392098
01:26:739 (1) - How about adding clap? I think it fits
Normal
00:40:506 (3) - Add a finish here would be good.
01:03:109 (4,1) - Put the new combo on (4) instead of (1)? The symmetry you used here looks better if it has the same color.
01:19:958 (1) - Put a curve like this?
http://osu-ppy-sh.tvgratuite.org/ss/392108 looks pretty bland if it's just straight.
01:26:739 (1) - Same as Easy. Adding a clap would sound good.
Hard
HP/OD -1 ?
00:16:054 (3) - Position this to x:396 y:168 for a better blanket with the previous slider.
00:16:876 (5) - ^ same issue. put it to x:288 y:224. Adjust (6)'s spacing if you followed this.
00:24:273 (4,1) - Since this is stacked. I'd prefer you to put the New combo on (4) for less confusion.
00:31:054 (4) - How about like this?
http://osu-ppy-sh.tvgratuite.org/ss/392112 I think it flows better.
00:37:219 (1) - Put a little bit more curve on this slider please xD
00:39:684 (1,2) - Add claps on the whole slider?
00:40:506 (3) - Add finish please and New combo please.
00:41:534 (1) - remove New combo.
00:42:972 (1) - Not sure about this.. but the rythm feels awkward. Remake it?
00:58:999 (4) - Same as 00:37:219. More curve please xD
01:04:342 (2) - NAZI but this here's a better adjustment.
http://osu-ppy-sh.tvgratuite.org/ss/392118
01:15:438 (1) - This looks pretty bland. put a curve.
01:25:917 (2,3,4,5,6) - How about some claps here too? this is following the drums right? xD
01:26:739 (1) - Same as Easy. Clap please
Insane
Circle -1? I like it better with that.
00:02:287 (5) - Add whislte here too.
00:05:575 (5) - ^ same
00:06:910 (2,3,5,6) - Add claps
00:07:630 (7,1) - New combo on (7) instead of (1)?
00:13:178 (6) - move your 3rd way point to x:56 y:288 for a better blanket.
00:39:890 (4,5,6,7) - Starting your triple on a red tick is bad. It plays better on a white tick just like this
http://osu-ppy-sh.tvgratuite.org/ss/392132. Also don't forget to put claps.
00:40:506 (1) - Finish!
00:41:739 - Add a note with clap?
http://osu-ppy-sh.tvgratuite.org/ss/392135
00:54:890 (1,2,3) - I think this part would good as a slider with reverse as well. Something like this?
http://osu-ppy-sh.tvgratuite.org/ss/392140
01:09:273 (1,2,3,4,5) - I'm not sure about this.. I think it could be done better. remap it?
01:26:739 (1) - How about putting notes here instead of just a spinner? This is already an Insane putting in just a spinner would be a let down for me

This is a nice map! Good luck Genkishi! go for rank! \o/