Fun game ^^ I enjoyed playing through it ^^ There's a few thing that can be improved in my opinion:
-The shield: It doesn't feel good. I didn't use it because its too small and directional. If you want to improve it I think you should make an Into the gungeon blank bullet type of power where every bullets on the screen disappears.
-The stun/knockback: It's a fun mechanic but the circle in which the stun applies needs to be more visual. This is especially true for a game jam because the players most likely won't spend time to learn the distance. Another way to fix this would be to make it bigger