the list is so terribly long, they skipped almost the whole impossible mission aspect, jihu joining the delphine girls team, his talks with kim hannah, the entire sceherazade bit (i have no idea how to spell it) what happened when he went back to earth, the girl who was in the carriage with them got cut out, they didn't fight the creatures, in the webtoon carpe diem didn't put up a hiring sign that he saw gold, in the novel nobody ganged up on him, they didn't scout him, he found them, went to their building and had to convince them to let him go, the call with taciana cinzia, i have no idea who that 'master' guy is and if it's who i think it is he shouldn't be here for for a very long while. they didn't even give the pervert wizard guy a name, it's ian denzel by the way, he should have been introduced earlier. if the 'master' guy is ian, it's just wrong. also there's like zero introduction for any of the characters, in pretty sure in the novel they tell him their level and class. there's more but i don't remember the earlier arcs too well, i know there was a lot more wrong abt the tutorial arc that i've left out my memory is shit and it's been months since i've read the book, so some bits might be a bit inaccurate in this whole thing, but for the most part yeah. it's not even close to the novel.
also i would definitely recommend reading the novel ! not too sure what you mean by harem aspect, theres really no harem at all until the very end, all the girls in the story are strong on their own, and aren't really clingy or obvious about liking him. minus teresa hussey lmao but that's her personality
i haven't read the last 20 or so chapters, but up until about there there's almost zero harem it's kinda just flirting here and there, i don't wanna spoil too much but he gets a p stable relationship with a later introduced character for a little bit, which i guess ends somehow with him marrying them all idk i'm not there yet
i like it but lmaoo this is like a completely different story from the novel :|