Visuals are stellar! Especially with all of the added effects like text waving on hover, and all the other little animations!
Movement feels good, and dashing also feels great. Its very enjoyable to dash and weave through endless hordes of bullets.
I was able to beat the first 9 waves pretty easily through just spam, but after 10 it got much harder. I think some of the difficulty spike comes from the sheer amount of bullets on screen. If you were to expand and make this longer, I think what makes bullet hell games fun is when the bullets are in some sort of pattern, and have predictability to them, but that's hard to implement when you're meant to deal damage to yourself.
At times I would lose my cursor within all of the bullets, which would make it impossible to aim. Maybe give it a thicker outline, or some distinctive feature.
Health bars for enemies would also be a nice touch, since then you would be able to converse your shots more knowing how much health each enemy had, instead of shooting way more than you needed. It would also help with knowing where a open spot on the map would be.
Great job!