I read the manga and it was horrible. The main protagonist is dumped because of a weakling he is.
Then of course his only motivation to clear the dungeon is revenge. He goes from goody two shoes to a harbinger of death..?
The girl who seems full of sunshine and rainbows turns into a bitch and then.. ahh i don't feel like talking about it. Characters are too bad. I haven't seen worse. Okay I did (SAO), but still.
The fights have no logic. The mc can doge easily etc etc because his agility is high? That's an asspull because there were monsters who could kill him easily in the beginning but didn't because he is "the main protagonist".
The ending was all over the place. The ending was so bad that hunter x hunter (2011) ending seems better. The ending brought new character which was never introduced or mad a hint before.
The ending is not really an ending as I believe they intended to make more manga.
Anyway I will end my review here by saying don't read this manga, there are better ones.