The peeps who are giving this manga this low a rating must be the people who were disappointed that their MC was not another "Harem king who one shots every enemy around him but still acts like a dumbfuck". This is the manga which will come around my mind whenever I say "Yeah this is why I like Isekai". While reading the manga, I thought that the author has to be a gamer by the way he exploits the elements present in games in real life and uses them in his work so beautifully. I was able to believe that the story is based on "isekaidin a game" cause the setting was able to make me. I played Pokémon especially White 2. I no-lifed the shit out of that game when I was young. I seemed to connect to the manga and compare White 2 with the game that the author presents. Glitches, grinding spots, strategies, strong and weak equipment, training specific stats, etc. you name it all, it has nearly all the elements which makes a good rpg game. With the differences between the things you can or cannot do explained while playing the game in the real world or while being in the game world is very interesting. What is also interesting to see is that an author giving their time and effort to make it believable that the current world was once a game to begin with instead of opting the easy route out.

Characters so far: Outstanding
When at first I was reading I was like "The MC will definitely be another OP isekai protagonist". But rather than being an OP protag he is the teacher of the OP protags while being very weak himself. Thank god, the author gave this dynamic to define the relationship with some other characters and not the harem one. The students are also very good characters. They have showed more character development in a month than some characters don't achieve in their lifetime. I did not find any character to be annoying per se, some actions excluded.

Story also so-far-so-good. The way the MC uses elements present in the game which is now the world he lives in, is somehow realistic to see, that he has played the game for an absurdly long amount of time. He knows what he has to do in order to achieve something. And he does it in a way a long time veteran would have done. While the story has the usual endgame of defeating demon lords, it sure makes it interesting and game-esque.

Tl;Dr: An extremely good read that you have to read