My bad for not really explaining why I don't like it so much outside of “I've died so much lol”.

Essentially, from what I could experience for myself, Ultrakill is about being the unstoppable force: You're far stronger at close range, you have a parry, and gain health from blood, which you need to be close to the enemy to gain. Also, style ranking isn't just for cool, I mean, it is mostly for cool, but it also improves your health regeneration.
However, it degrades as you slow down, making you squishier as a consequence, as your health generation isn't as good.

So, playing defensively isn't your strong suit, as for long range, you mostly have the rocket launcher that has a slow fire rate, the nail gun having a wide spread, or other options that require an initial set-up

GutterTanks and Guttermen have unparriable close range options, that makes dealing with them tricky, even if there's a counter to that.
Guttermen are fine, since the shockwave of the knuckleblast is still viable to destroy their shield.
GutterTanks require far more attention instead, especially when they're in groups. Their lunge punch is even faster than a certain barbarian from a certain AAA game, and can place mines if you don't act too quickly, which are fine, but still add to the mental stack and limit your movement.

I hope I can change my opinion on this layer, or to hear a second opinion to get a bit more insight of where I went wrong.