A fun journey! Nice tonal shifts in the beginning section. My ear really wanted to hear a high-register octave during the empty space around 0:19 as a little ornamental afterthought. As a pianist, I would rather just read 15-22 as a regular treble staff.
The transition away from tonality was elegantly executed, though I think the rhythmic energy should be kept up at the secondal bit.
Also, I didn't even register that the opening was in 5 until I looked at the score- maybe it's because 5 doesnt sound weird to me anymore