The start was pretty acceptable, even if it was a SAO copy I'd still have tolerated it (mainly because of the BASED self sacrifice moment) if everything after it did not utterly suck and confuse me.
After the start, it copies like, half a dozen different tropes very poorly. MC suddenly has a little sister, does not question it whatsoever, titties fucking EVERYWHERE, feel like each chapter I was seeing censored boobs, which I don't hate but I ain't here for that. Out of the three years he was in the VR game, only three days passed in the real world and suddenly everything went to shit and started copying the video game world, again, could be good, executed awful here. MC also then forgets about his comrades of three years, despite the fact that they were the ONLY family and friends he had, defeating the point of the grand self sacrifice at the start. He then jumps straight into academy life after high adrenaline battle for three years straight and literally fucking dying. Even SAO was better than this slop.
tl;dr It's like they put all of their budget into the first chapter, realized they had nothing else for the entire rest of the story, looked at the front page at what was trending, started frantically copying everything they saw, found a porno in the middle of it, had a wank, and continued writing.