In what way does your game fit the theme?
Bullet hells are probably the most obvious answer for the theme. Bullets hells are very chaotic, right? But the player is often very slow-moving, very calm, in spite of all the chaos around them, because it's easier to manage. Even though there might be a lot of things on the screen, you just have to focus on yourself and let the chaos exist.

So for me, it's a very interesting design challenge. We have this genre that's very crazy, tons of stuff happening. I wanted to take this as an opportunity to study and try out different patterns and groups of enemies. It's very easy to throw a bunch of enemies on the screen and call it a bullet hell; it's much harder to make it fun. I made sure to add as little RNG as I could - I can guarantee that there is never an unwinnable situation, and it lets me more easily control the types of patterns that come out and the space the player is allowed to be in.

On top of that, I added the sync system, incentivizing the player to play a little more aggressively, and the score system, which is my way of adjusting the difficulty curve. You're given higher score based on the amount of bullets on screen (logarithmically), so more experienced players can let enemies survive for longer, creating more chaos.

Did you write all the code yourself and made all the assets from scratch?
Yes, all but the spline code, which I implemented based on CatLikeCoding.