Awesome game! Really interesting dynamics between the two. I love the simplicity of the shapes, but how well it's all explained in the levels - it was easy to understand what's happening.
It's a pity the music doesn't change on its own! If I hadn't known about the Q button, a lot of interesting tracks wouldn't've been heard.
For the last level, I'm not sure if I solved it correctly, I had to click-frenzy my way up out of the tube
For suggestions, I'd even out some terrain (sometimes gets stuck, very minor) and also add the Restart Key binding to the description, I had to restart the game to find it in the Controls section.
Great job!! Will recommend to some folks :)