An effective bullet hell, well done! I like the art assets you used!
I'll admit, at one point I tried to access the menu by pressing escape and instantly restarted. I think tying "instant restart" to that key is a debatable design decision, especially since Escape is often used to free the mouse cursor from other types of browser games (or to open the game menu).
But the enemy designs are very good, and in general this is well-crafted. Great work overall!