I honestly like the art direction, it definitely has that comic book vibe that Hirano Kohta was going for in the manga.
Speaking of, legit, if you've only seen the anime, you owe it to yourself to read how Kohta truly envisioned it. Yes, Ultimate ultimately is the way to experience it because of how it's presented, however, it is thanks to Kohta's visionary that it flowed as well on-screen. There's some legit cinematic paneling throughout the manga and the characters are much more striking in black-and-white, and you can just see the raw batshit insanity the mangaka pulled from his brain (when he felt like it that day). Even the English translation had fun with how to portray accents with various characters, it's probably the closest to your typical Western comic book you'll see out of Japan, and you could honestly breeze through a volume in less than an hour if you want the action to move fast.