Frankly fascinating !!!!! It is a perfect jam/art experience game !!!!! One thing that could be cool gameplay wise: right now you can only fill area you emptied; why not gather mass you can use to fill empty black areas ?
That's a brilliant idea! I've begun fleshing out a full game based on what I've submitted here, and I'm definitely in need of more interesting mechanics to fill in the 3 chapters I have planned so far, so you'll likely get your wish
