Left a rating a couple of days ago but didn't get a chance to leave a comment till now... I love this concept so much! Funnily enough, I was originally working on a mouse-based battle system extremely similar to this one (minus all the cool visual effects) before the project grew out of scope and I moved to something else. I didn't get very far, but I got far enough to say that I really like your implementation, and I also love how the bullet patterns are designed in such a way that they encourage different types of movement for different enemies. Combine that with the art and music and the tightness of the gameplay loop... I think you have something really special here, and I'd love to see it expanded if you decide to work on this in the future. Amazing work to everyone involved!!