These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fridge Brilliance: During the sequence where Aoba uses Scrap on Mizuki, letters start start to pour out of Aoba's body and appear in front of him. This freaks him out and he runs off. The letters were probably going to form a word puzzle like in Koujaku's Scrap sequence, but Aoba didn't know what he was supposed to be doing. Consequently, the player never gets a chance to solve the puzzle, and Aoba inevitably fails to save Mizuki.
When Aoba runs away from the letters, you hear the same laughter that happens when you make a mistake during Mink's Scrap sequence, although this might just be the other people in the room.
Fridge Horror: No matter who's Good Ending you get, the other characters are left off dealing with their problems for possibly the rest of their life. Koujaku will never get over his self hatred and guilt and his love for Aoba goes unrequited, Noiz will still be unable to feel pain, Clear, Ren, and Aoba are left off not knowing about their true origins and the existence of Sei, and it's heavily implied that Mink committed suicide
Memetic Mutation: "iiyo" Explanation Near the end of Koujaku's route has Aoba repeatedly say "That's fine"/"iiyo". In his bad ending, he won't stop saying which causes Koujaku to scream. Fans found his scene scary yet hilarious.
"You fuck the Dog" Explanation Ren, Aoba's allmate, who takes shape as a dog, has a route and in the good ending he has sex with Aoba, in his online form.
To a lesser extent, it has been argued that "the dog fucks you".
"Mizuki got friendzoned." Explanation Mizuki, one of the few major characters, does not get a route as he spend the rest of the game in a deep coma. (He does have a route in RE:Connect though, but it takes place after the good endings, which at that time Aoba has a boyfriend)
Koujaku's Adorkable personality can fall into this
Narm: Many fans have pointed out when Toue says how he'd like to find a way to dramatically murder someone, it was in no way elaborated on. The thought-to-be Title Drop was so incongruous, fans have made fun of it.
The "glitch" in Noiz's route, it can be unsettling to first timers as many thought their game is literally crashing.
The "iiyo scene" in Koujaku's route (more specifically his bad ending). Though to some, it's Narm Charm.
One-Scene Wonder: Sei has only appeared in the good endings, and you don't find out who he really is until Ren's route. THEN you only get to actually interact with him in Ren's good ending and that is when he dies onscreen. and yet he's one of the most recognizable characters and is probably the biggest woobie out of all the characters.
The Scrappy: Mink. If raping Aoba, continually abusing him wasn't bad enough, he is the least romantic. In a BL game (even if it is a N+C BL game)
Although, Shiki goes through a lot of character development throughout Tn C that Mink does not. Especially if you listen to the Drama CD which is in Shiki's point of view, it turns out he ad libs through much of his interactions with Akira.
It's a double standard even in the context of the game. Specifically, Mink is reviled for his rape and abuse of Aoba, but Virus and Trip not only get a pass, but are wildly popular and are many people's favorite characters.
Unfortunate Implications: Maaaaaaaybe having the dark-skinned dreadlocked warrior be the resident Bastard Boyfriend to Aoba whose very introduction is getting his gang members to attempt to rape him wasn't the best of the ideas Nitro Plus Chiral had for the first game... At all.
The fact that the normally hard-headed Aoba simply accepts his treatment at Mink's hands,or never tells anyone about how they met, makes the relationship seem like the typical "Jackass Seme rapes Uke and they fall in love" plot, at worst, a terrifying tale of Stockholm Syndrome.