The MC is crazy overpowered, and there's absolutely no tension left in the story because of that. There's no point in the last 50+ chapters where I at least somewhat could think he might've died because he NEVER loses. The plot is super derivative. Weak dude suddenly gets blessed with amazing powers and becomes an awesome hero, showing up all of the lazy corrupt strong dudes who look down on anyone lower than them. And the monsters are all generic video game villains like orcs, dragons, knights, elves and wolves. There's nothing about the story that sticks out.
The art is good. The glow and blur effects really add to the sleek aesthetic of this manga. As for the art style, it's pretty generic but that's not really a big problem. The big problem is that none of the character designs are unique. Many popular anime and mangas have characters with really iconic costumes and designs, but this manga has none of that.
There was some minor character development in the protag in the first 20 or so chapters but since then he's just been an edgy edgelord (seriously, is the dude literally incapable of wearing midnight black clothes for once????) Since he's killed so many people and monsters, and since both people and monsters have been shown to have some good ones among them and some bad, there's plenty of room for a moral conflict there- should he stop killing everyone so mercilessly and give them a chance to change? Or is he in a kill-or-be-killed world where compassion becomes weakness? The writer completely ignores this potential oppurtunity for giving the story some depth and instead goes with a story revolving around the edgy edgelord clashing with an big angry demon in a big fancy smashfest, each one more grand and explosive than the next.
No one else besides the MC even gets any development. There were some interestingly conflicted characters at the start of the series but now they've disappeared entirely. The women are few and far in between and are pretty much all weaklings who never get a cool moment of their own.
Immensely disappointing. The only reason I bothered to read the entire thing was because I wanted to see how it would end (the series looks to be ongoing so I didn't get to find that out.) The story and characters are flavorless and boring, and the writer did absolutely nothing unique with this manga.