I'll start with what I like about this novel.
1) In general, it's just a pretty solid LitRPG. The progression is interesting, and it's an enjoyable read.
2) I wasn't expecting this novel to have such an interesting and engaging mystery. Finding out secrets about the game, its origins, its connection to humanity, etc. is really interesting and unique!
Now for what I don't like or am not as big on:
1) The names of items/skills/classes/etc. are very inconsistent. Some people have said it might be a machine translation that can't keep the names of the same thing consistent, but whatever the case, it's distracting and hurts the novel.
2) The people in the novel have crazy mood swings when faced with difficult challenges. They go from calm to panicking to bloodthirsty to despairing to hopeful to calm again in mere moments. Most of the players have no sense of perseverance or bravery. When faced with a fight that they probably can't win, they usually just give up. Even when they're supposed to be people that have played the game for decades or even centuries and have painfully raised their strength to the level it is now. You'd think they would be a little invested to the point of trying until the end. But after having played the game and struggled for so long, they never developed any emotional intelligence. They still have the mood swings of teenager.
3) Sterl isn't a bad character, but he's not a very consistent character. He supposedly only acts for the benefit of himself and those he cares about(his harem). And any extra good he does is just if it's easy and while he's doing other things. That sounds like a character that would be good at his core, but he also has sacrificed human babies for rituals without batting an eye. My problem isn't him being good or evil. It's him straddling the line too much to be consistent.