Awesome stylish project!

You have a README which is great, but you'll need a License file as well (these are two main criteria for open source category). Maybe add some emojis and screenshots to your README to make it a little more interesting. Great job on your repo though.

I enjoy a good full window game by default. I would have the first level much simpler to get the hang of the controls and sensitivity of them. Maybe have the first level as is without the giant rock immediately as you start playing. Add some effects and music and this would be more immersive. Art style is really great and your game nicely fits with the balance theme. Kudos.