It took some time to realize that there is a kind of canon in the piece, even 3 voices in the end, amazing beautiful, but hard to discover which notes to play.

The file is not played but mixed as a canon (or echo), it isn't possible to play it as a that on a piano, it would be too chaotic.

I got this question about the piece: Is this on the G flat key?

Answer: If you want it could be G flat lydian mode. Or B flat minor. I think those pieces don't 'use modes' anymore, influenced by Jazz or something.. Because there is too much of changing chords to assign them to one key.