This is an isekai where the MC is transmigrated to the world of a very difficult game after beating it. I find the art and story to both be superb. There is clear character development with the MC as he slowly stops treating the world exactly like a game.
There is a city that many races live in, and, like any city, there are taxes. Except in this city, the penalty for not paying your monthly taxes isn't jail or even banishment; it is death. The best way to make money is to dive the dungeon that opens once a month, but it is also the most dangerous.