Yeah, I can see where you're coming from, but I think the fact that the bullets were so fast made the game more exasperating and luck based during my runs. I didn't feel euphoria when I escaped by the skin of my teeth, I felt lucky. (If I felt anything. Usually I wouldn't even notice).
The specific feeling I'm thinking of that I think you want to try to avoid is the "I sure hope I get the number of bullets right otherwise a bullet is going to fly straight into my face and there's nothing I can do about it!" Making the bullets slower and predictable would fix this problem since shooting too many bullets makes the game harder but not impossible. Making it so you have control of the number of bullets fired would also fix the problem, but would go for an experience more akin to "shoot x number of bullets and don't miss" which I doubt is the experience you want the player to have.
Eventually I just said "Screw it" and would stand in a corner firing bullets in a giant stream that would consume everything until either a bullet hit me in the face or the portal opened, and I'm pretty sure that's not the experience that you were going for as the developer.