I like the 12th jacks, nice catch.
The gradual buildup in difficulty across the chart is good, because it would get boring if it didn't do that (needs a bit of a fix though, see 22.680)
(all times are in seconds)
15.750: This blue jump should just be a single note because there's no bass kick playing here. (listen)
17.400: Missed a 24th snare hit just before this.
22.680: My gut feeling here is that the new melody needs to be expressed. Constant 8th jumps seems overkill (and you do it later anyway), and so does constant minifreezes to it. I'd suggest either putting holds to the melody that's always been there (so it FEELS more built up) or re-arranging the patterns so it forms a slowly meandering trill with jumps thrown into it. Oh, I thought of another way: Layer percussion when it plays without the melody.
59.640: This freeze should be a whole beat long, remove the 8th freeze after it.
Fix those, make the rest of the difficulties and it'll be good to go.
