Some wasted potential, full of worst tropes, lacking direction, stupid inconsistencies, childish edge without point for 12yo wanting to think they are sooo mature for watching such incorrect story.

Characters are constantly (and there is no way to emphasize it enough how much) explaining to each other things obvious for them. If you think any of your childhood favorites like Pokemon, Yu-Gi-Oh, Naruto or Dragon Ball lacked in show-don't-tell, this anime could help you rehabilitate those. The show is unable overshadow a single thing, and when we see attempts of thrown hooks for the future, they very rarely lead to anything.

Main character in this story can never suffer from power creep as it is established from the start, that he is as powerful as can be. It is basic premise of the story, but it is utilized very badly. There are some hooks thrown that could turn it into actually good thing, but they never do.

Main character (in simple terms) balances between his own heroic and villainous motifs, tries to keep a villain mask in front of his evil clique while justifying his heroic deeds as a tool. While this dynamic could be a good thing, his inner struggle is exposed only incidentally, and his actions aren't playing into it very often. Many instances of pointless malevolence exactly when heroic twist could actually make sense, while his ability for rather blatant justification of heroism for little gain was established early on. It is rather a writers' tool to use for shock in the story. Like, oh, you liked that person, who had some unique characteristics that obviously main character would want to exploit, so he will save them in the end, just like we've shown you with others? Think again, sucker XD After a while you can expect stupid resolutions for shock to happen more often than not

Game-based Isekai world has features completely incompatible with any reasonably imaginable game, however advanced it might be presented as. One example especially is full-time-stop spells/abilities. I mean, yeah, cool thing, and plays into overpowered dude overpowering all around, but how THAT could have been implemented is beyond me, and that is just one thing that makes you asking questions about this supposed game. Show is full of (MMO)RPG mechanics lingo used in-world, and while that might have its appeal, it seems to often be thrown rather randomly. There are named: classes, specific abilities and spells, spell level rankings, guild membership rankings, magic thingamajigs of various levels - as derived from the game mechanics. But almost all of theese have little consistency and little consequence for the actual plot, as new spells and artifacts come to the screen just when needed to show you, just how much of a badass the MC and his disciples are. The show pretends that the presented game had some mechanics, but you can't possibly learn from the show what to actually expect from it. One time we see character playing with vulnerabilities and resistances, and having to deal with huge amount of mana loss, other times the only way to win is to be helped by someone who can one-hit anything alive using just 50% of their power.

Best part of the show are some almost self-contained side plots and many quite complex characters, but in the end side plots are woven into hopeless main story and characters have no development over time. We also actually see some instances of attempts to play the show's many flaws as self-aware gags, but those are few and can't explain the whole show's poor writing.

Visuals are ok. They use cheap 3d animations for from-the-box monsters and troops, together with detailed classical 2d drawings for most things. While it might be clashing sometimes, it is at least of consistent quality. Most battle scenes are actually visually ok, have good variety in the scenes, without pointless prolonged hit exchanges with the same few frames looped for minutes.

Shows sharing some aspects with Overlord for you to watch instead, with various but all better quality: Death Note, Code Geass, Log Horizon, Re:Zero, Sword Arts Online, Sekai Saiko no Ansatsusha. And if you came with a question what to watch if you liked one of those, then keep looking :(