This is an incredibly creative and original concept! It ties in with the theme of expansion brilliantly too, as the colors of autumn spread slowly at first. Until you realize the exponential nature at it’s core!
Although your entry is simple, I have to commend you on nailing what you do have here. The art is a perfect match to the gameplay. It has that timeless feel to it.
I see you have planned features already which is great to see. The right music and sounds could really add some magic to a game like this. However, I am surprised to see no mention of adding SFX, BG ambience or music. If this is because you just don’t have anyone to provide this, please reach out to me. The only thing I know is audio, and would love to help you bring this project to life!
That was basically my entire contribution for our entry PopRocks. Have a look if you’re curious.
This is my personal pick for most underrated entry.