Read 72Ch. #68
The whole premise is misleading, he doesn't reincarnate each time, he resurrects from the dead. So no new worlds. (Although this is stated in the first couple chapters).
The MC seems like he doesn't age, although he gets older, his personality stays consistent, never improving. The author also tries to include character improvement, but its done in a jokey way and for such basic things. Like the MC eating random mushrooms, which he should've known not to, since hes lived for like 50+ years at that point. And at the end of each of these segments, its always the MC talking to his dog "lets never do that again".
Theres very little emphasis on martial arts, (at least up to what i read), it is a big part of the world, but the author barely goes into any detail, and after the MC's first couple lives he doesn't seem any wiser about martial arts. He just gets a manual and follows along.
Also, every time he "reincarnates", his body is supposed to go back to the time he went to this world. But somehow he keeps his inner qi? and doesn't have to retrain his body at all. Yes his first "cheat" is doubling his strength, but after the first time it isn't mentioned again.