This is very simple, like, too simple for me to really say anything about it, so I'll owe you this one sorry x3
Menu music is catchy and I like slugun, so I guess there's that.
Only comment I have for real is that hitboxes are ridiculously big, way more than they would be acceptable. Like, even while crounching I still got hit despite not touching any bullets at all. Remenber that you always need to keep your hitboxes smaller than your sprites, and for a bullet hell you need to take that to the extreme. When I booted the game up I instantly assumed the eye of the char was gonna be the hitbox, it would've felt way better if this was the case.