I like guns. I like cute anime girls. I love cute anime girls with guns, and I ESPECIALLY love cute anime girls with guns in a series revolving around those. Given a hefty side of "these newfangled deadly contraptions are foreign to our world and BTFO anything we try to use against it" and I should adore this series. So why don't I?
The story is bad, putting it mildly. It's predictable, uninteresting, has some of the WORST cringy dialogue I've ever read (to a point where the dialogue can't even be funny bad), the story is all over the place in terms of pacing, and it takes itself WAY too seriously. I'd rather subject myself to SAO in its entirety than this.
The art also doesn't do it any favors. It's passable in some places, but just plain bad in most others. Aside from a couple key moments, it just doesn't look good. Even the guns, one of the key parts of the series, don't look great after a while, especially when they're constantly put out of frame, hidden behind an ink splotch that's supposed to be a muzzle flash (after the characters spray randomly and somehow kill everything in a single frame of action), or look like they were lazily pasted in as an afterthought.
The characters are bland and stale archetypes. Poorly written cardboard cutouts that aren't interesting in the slightest. I can't even bring myself to like any of the girls for being cute, since they've got nothing really going for them. Maybe the demon girl, but she's only a little cute and had a good moment with her sniper, but she's been irrelevant to the story since that arc concluded, and it wasn't even a GOOD arc to begin with.
Honestly? If you're here because you're looking for the things I mentioned in the first paragraph? Save yourself the trouble and look somewhere else, cuz this ain't it. I tried to stick with it, but it's just unbearable.