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 Logic: Jackie lures Frankie and a lot of his mooks into an old warehouse, then drops a lit match through a floor grating and into a pool of gasoline, blowing up the whole building. But with that much gasoline open to the air, the mobsters should have been able to smell it from a block away and known they were walking into a trap.
So Jackie just found out that if he ever conceives a baby boy, he'll die. His immediate conclusion is that this means he can never have sex again, which means that life isn't worth living. You'd think he would at least consider sterilization as an option. Using protection might help, too.
Les Yay: The Angelus and her "companion" in the first comic arc.
Recently, the Angelus' host was a lesbian with a crush on the next host. Guess how they transfered the Angelus?
Once the Angelus finds a host, it seems to get a girlfriend quickly afterward, whether it's one they made - the thousand-year-old Angelus in the comic's introductory arc created herself a female lover as one of her angel army - or one they met, such as Dani Baptiste and her girlfriend Finch. Even Celestine had a weird fixation on Sara Pezzini. While it's never been overtly discussed, it's possible that becoming the Angelus host actually makes the host a lesbian.
Acceptable Targets: In the game, you are sent after drug dealers selling to kids (because they are encroaching on the Family's territory).
More generally, all of the people Jackie has to kill in the game are either mobsters, corrupt cops, mob affiliates, or zombies.
Complete Monster: Paulie Franchetti adopted the protagonist of the game, Jackie Estacado, so he could mold him into a hitman loyal to the family. The game starts with him sending Jackie on a suicide mission to kill a business rival because Jackie started questioning the way he does business, but he has already killed the business rival and strapped his corpse full of explosives as a birthday present, leaving a tape to mock Jackie before he died. When Jackie survives the blast, Paulie gets revenge by blowing up the Orphanage that Jackie grew up in, killing all the orphans and nuns inside and then telling Jackie over the phone it was all his fault. When Jackie starts to ruin Paulie's business dealings in retaliation he kidnaps Jackie's girlfriend Jenny, brings her to the Orphanage and then murderers her right in front of Jackie, blaming it all on Jackie for not blindly following orders. Even at the end he shows no remorse for his crimes, telling Jackie that Jenny was a weakness and Jackie shouldn't have cared about her death.
Crowning Moment of Awesome: When Jackie finally takes full control over the Darkness in the fourth chapter. Shame it doesn't last...
Game Breaker: In Vendetta Co-Op, once you purchase your character's ability to restore health by performing executions, you can just rush into combat and chain together executions of Mooks ad infinitum until you've beaten the game. Only bosses will slow you down, since you can't execute them.
Moral Event Horizon: When the Darkness forces Jackie to watch, taunting him all the while, as his girlfriend is murdered.
"Awww, what did they do, Jackie? What did they do to Jenny?"
In 2, the Brotherhood crosses this all the time. The ambush at the restaurant that killed innocent people? Them. Then they assault Jackie's house for the sole purpose of killing his Cool Old Lady aunt. Then they attack the aunt's funeral just to lure Jackie into a trap.
Player Punch: I see you're near the end of the first chapter. Better prepare some raw steak for your eye, and possibly a stretcher.
Unfortunate Implications: The entire NYPD are portrayed as sadistic bad guys. At least, the ones we see who work for Schrote. If there are honest cops in the setting, we certainly don't interact with any.