Wow, this is good! Your vision for the game is super well translated into the music and it all has a really immersive atmosphere. The overall soundtrack has a cool progression to it that I feel would fit an actual exploration game quite well. I also really appreciate that you kept each track simple enough to let its strengths shine and build a unique feel! My favorite part was the return to the title theme in Dawn Chorus.
Also thanks for linking the sample website :)