I am looking for something good which has the concept of returning to the past. I have read some and am currently reading Reincarnator but this also doesn't live up to the mark. The starting was good but right now I am at 300 chapters and it is getting very hard to read. I have read Seoul Station's Necromancer but it also became very bad at the end. So something like these two which means with game elements and levels will be appreciated. I am basically looking for something very good from the start and can maintain it throughout the story and not just plummet in quality towards the latter half of the story. If possible try to avoid harem tags. As they usually don't really go well. The only harem light novel I have that I really enjoyed and was happy for it is a harem novel is "Everyone Else is a Returnee". But that is an extremely good novel and I am not expecting others to make the harem label that good. And the ones that are complete will be more appreciated.
https://www.novelupdates.com/series-finder/?sf=1&tgi=93,2571&mtgi=and&sort=sdate&order=desc Series Finder function is very handy.
I can recommend you two that, while not a complete 'return to the past', run with the concept of having foreknowledge but not because of simply reading/watching the story but having been part of it before. The Novel’s Extra I Reincarnated For Nothing Obviously they're very good even looking back months (or years?) after completion. You might want to look in the recommendations of those if they catch your fancy. Edit: Nvm, the links are dead.
While there's no game system or game elements, Reverend Insanity/Daoist Gu's MC returns to his past. Actually there's a lot of novels with regressors, or equivalent. Reincarnator clone: The King of the Battlefield (it's pretty meh imo though), some other novel I forgot(?) MC played a game before transmigrating into a fantasy world that's just like the game (and they appear at the beginning/just before the start of the game's setting): The Amber Sword, Abyss Domination, Night Ranger, Advent of the Archmage, some more DND novels, https://www.novelupdates.com/series/kono-sekai-ga-game-da-to-ore-dake-ga-shitte-iru/ (this one's less serious and more about the fun, but it's pretty unique and interesting) MC read the novel and knows future events: Omniscient Reader's Viewpoint, The Novel's Extra, every novel with villain or villainess in the title MC returns to the past before playing VRMMORPG (and it's still just a game): Rebirth of the thief Who Roamed the World, Reincarnation Of The Strongest Sword God, some other shitty ones like Reign of the Huntress Then there's a bunch of return to the past cultivation novels, Limitless Sword God is the first one that comes to mind for whatever reason (besides Reverend Insanity ofc), but you wanted game elements right...
https://www.scribblehub.com/series/43422/the-grandmasters-weird-disciple-bl/?toc=17#content1 This one is BL, but it is very good at showing the MC the stuff he did not understand the first time through his life (like common sense!).