I listened to a few of them, and enjoyed them.
With "Farewell", I really enjoyed it up until 1:35~ when it abruptly changes. For about 20 seconds, it's as if an entirely different song was in there with (to me) no relation to the original song, before returning. It was a bit jarring, but not in a good way. I enjoyed that style of music though - but it was just too disparate from what was immediately before, and immediately after. I like changes in music, but (in my entirely musically-ignorant opinion) the changes should still share common threads and flow together.
It just stood out extra, because the rest of that song was very excellent. I love the transition from the original song, and I also love the skillful way it transitions back into the original song. The transitions were great, just the area between felt like they belonged to a different track.
I'm not a musically-inclined person, so take that with a grain of salt. Overall, I loved it.