The idea of the nodes is so interesting. I couldn't finish with that circle that attacks you and I would play again to see what happens when you finish it :)
What happend that you couldnt finish? Because it is the first of four bosses if you fight them in order. You can defeat him quiet easily by farming nodes for a while til you get a Node which increases the bullet count. (You can defeat him without getting more projectiles, but it makes the game much easier). Still thatnk you for you comment.