I'm glad to hear you think that because I felt as though the key-change had the grace of a sledgehammer smashing pottery, lmao. I appreciate the kind words and you taking the time to check it out and comment!
The piano itself has no saturation directly. Booted up the project file again to refresh my memory and my chain was basically: Compressor → very light diffusion reverb (helps add some grit for future processing) → split into two sends, the first of which has 2 separate resonators and some more diffusion reverb / the second has a delay (slightly reduced sample rate and tone rolled back) and then processed through some very light shimmer reverb (to add back onto the highs) → both of those sends then return to the one track which is then ran through a driven low-pass filter and has a soft tremolo to add some movement.
I'm glad you like it! I wasn't sure if it'd be too muddy and bordering-on-clipping for people's tastes but I simply loved how moody and gritty it sounded.