- The sexual stuff in this singularity felt tacky and was there to show off the writer's fetishes. The constant sex jokes about Fergus' adult self and all the femdom stuff felt in really poor taste and were really unnecessary. Also, outside of the Amazons, the male enslavement stuff didn't make sense for the other two rulers and it had no connection to the main villain's motivation except some vague allusion to her fearing men which even then makes no sense given she could just have a society without males.
- Mash and Da Vinci were honestly at their worst here. While I enjoy them both as characters, they felt really annoying in Agartha from the fact they literally sent you to a singularity without servants and got mad at the guy who smuggled in Astolfo and D'eon, the million times they had to remind you that Columbus is not good as a way to force foreshadowing that Columbus is bad, and all the comparisons they kept telling Young Fergus that his older self is a pervert despite the fact they have dealt with alternate forms of servants before and they never reminded them of what their other selves are like. Speaking of which, them yelling at Columbus for being evil for slavery is really stupid given they have teamed up with various heroic spirits who owned slaves (i.e. Gilgamesh, Ozymadias, Francis Drake who Mash admires funny enough, and many more who actually did worse than Columbus) felt very hamfisted.
- Fergus Lily is literally the worst fate character in the series as all of his dialogue consisted of how he doesn't want to hurt women, loves to train, hates his older self, and has very pretentious monologues about how each of the rulers have ruled as though the game wants to make them look sophisticated despite openly torturing men for fun and pleasure. He also does nothing and comes across as really annoying especially given they try to make him look cool but comes across as annoying. It doesn't help his character comes at the cost of bastardizing the original Fergus who I'm not a big fan of, but they treat him like he was only a guy who loved muscles and women even though he had more class than that. His speech at the end of the singularity was really cringey and if it wasn't for the characters I liked, I would've skipped the story.
- The Chaldea servants being corrupted really did nothing for the plot except shock value and were excuses to bring things in. Helena's only purpose in Agartha is to drive home how evil Columbus is and provide a deus ex machina, Drake being in Agartha was because the developer got lazy to design Dahut and used Drake for shock value because Dahut was too generic to do anything on her own, Heracles was there to provide a boss for the sake of a boss and because the Prillya writer only views Heracles as a brute despite having gentle giant qualities, and Fergus Lily was to have some arc about kingship that was executed really poorly.
- The villain reveals were really lazy and had no foreshadowing. The closest Columbus had to being evil was Mash and Da Vinci constantly reminding you how evil he is because of similarities to Moriarty that had to be told to you. This makes his betrayal less shocking and he was evil because a villain was needed to pad out the game as he was only a villain for like one and a half chapters. Scheherazade had no foreshadowing whatsoever except from a process of elimination which felt really cheap and there was literally a chapter of exposition just to explain everything as it made no fucking sense on it's own.
- Speaking of which, Scheherazade's plan is fucking stupid because she wants to create a faction war in an underground city which somehow needs males to be enslaved, and summoning servants for a "Story" just so she could enact her complex plan which is to lift the entirety of Agartha to destroy a city so magic could be destroyed which will destroy the servant summoning system. This is stupid because the summoning system would still be intact even if it is removed in one timeline and her plan isn't even threatening humanity either. It doesn't help that it's been established in the series that the Throne of Heroes exists in other dimensions/timelines so it wouldn't stop Scheherazade from being summoned by some schmuck in an alternate dimension. It's also inconsistent from how worried she was about dying to then basically committing a large scale suicide attack so she wouldn't be summoned again which would backfire.
- There were other minor things as outside of the very grating idiocy that plagues most of Agartha, Agartha is largely boring itself as it feels repetitive and the characters repeat the same phrases that it gets old. The missions themselves are just filler or you just fight the same enemies you had already fought with no real variation for the most part.