Thank you for the kind words! You are correct, currently there is no music in the game, hense why the master and music volume sliders are locked where they are in the settings. Maybe the decision to have them there but be locked was a little vague.
Incrementally sized maps are already in development, as well as rectangular maps and maps that are not regular shapes at all. Really glad you were happy with the game, and thank you for the feeback :)