Woah. I didn't expect to be taken on such a philosophical journey. Some really thought provoking concepts you've introduced here, all presented in such a peaceful and relaxed way.
While I was a little confused on what exactly the goal is with each level (like what needs to be done to trigger the next text), I totally get the intended vibe of discovering the game's mechanics and philosophical truths the longer you play! Like others have said, I enjoyed the puzzle mechanics introduced near the end! Deffs a lot of potential for expansion.
My only real issue is with the sound design. Don't get me wrong, the guitar background music is beautiful and matches the aesthetic perfectly, and the way each tap adds a piano sound, like it's adding to the music, that's also a wonderful idea! They just don't quite go together at the moment. Since the guitar and piano are in the same range, it kinda gets a little muddy when the two play together. Plus the piano sometimes plays notes that aren't in the key of the guitar tune, so sometimes it clashes too.
If you wanted to keep the idea of each tap adding to the soundtrack, perhaps you could have a bit simpler background music. A solo cello? Low, slow piano line? Something that the tapped piano notes would really stand out against, and compliment. It might also help to make the piano notes higher/lower so there's more range in between them and the soundtrack.
Otherwise, if you'd rather keep the guitar aesthetic, it might help to switch the tap sound to something more percussive. Woodblock? Water droplet? Something that doesn't have pitch. That way the two don't clash so much!
Well done with this unique entry! Keep up the good work!
-Sasha