Great game!
I love how intuitive and simple this game is. With many other jam games often having a bit of a learning curve to understand how the game works, it is nice to have one that just makes sense by playing it. The only thing that I got tripped up by was that my dashes didn't do damage, but instead killed the enemies and blocking is the only thing that does damage.
This is a very cool idea, and it really makes you think differently about bullets within a bullet hell game. Normally, when you dodge a bullet you just forget about it and keep looking at what is coming, but now you need to keep track of everything on the screen no matter what.
There are a lot of opportunities for new mechanics to be added as well, I was thinking about the possibility of different bullet types and such. Maybe some bullets that split into more when blocked, or ones that can bounce back into the arena after leaving only once. Lots of room for more ideas here.
The arena itself could also have a big effect on gameplay, a gap in the middle of the arena makes it harder to traverse and get to the other side if you need to be there to reach a stray bullet.
I realized how much of this game is about positioning, and enemy priority. Being far away from enemies that shoot many bullets can be detrimental since they will just go everywhere, so you need to be near them to get them while they are still clumped.
You could also continue to look at what various things bullet hell games give you to help you, and think of how to implement them into this. One that I thought of, was many bullet hell games give you some sort of "clear everything around me" option to get out of a tricky situation. What if, in this game you had the same thing but it pulled in nearby bullets?
I think that this game could benefit from a health restore when you complete a level, or some other form of saving, since it can be annoying to work all the way back up to the later levels. But I can see it not being a priority since there is only 15 waves.
Visuals were nice and simple, and the music fit well. (I loved the part where it stopped did the few beats, before coming back in)
Great work!