Jeremy/Adam's drinking problem is an open-ended question with a lot of mystery surrounding it, such as how it developed since Jeremy showed no sign of alcoholism as a boy, or how much it affects Adam's ability to function. On the latter point: is he faking it, using it as a cover for his behavior, or is being around his enemies making him drink more? Not only that, he only starts to hit the drinks onscreen after killing Ruthie, so is it possible he felt guilty about killing someone he didn't want to kill but he felt was necessary?
Campbell's death. Did Jeremy/Adam kill him out of pragmatism to make moving around the mansion easier or to emotionally break Dorothy and make her easier to frame?
Common Knowledge: Jeremy targeting Shelley, Lily, and Paige because they rejected him. While technically true, a Freeze-Frame Bonus on the document Kate is reading after Dorothy confesses mentions that they, along with one of the bullies, corroborated Dorothy's False Rape Accusation, which is why they were added to Jeremy's kill list. By the same token, Kate isn't targeted even though she also rejected Jeremy.
Critical Dissonance: The film was panned by critics (12% on Rotten Tomatoes), yet earned back nearly four times its' budget of $10 million.
What exactly is wrong with the killer (Jeremy) isn't explicitly stated, but there was clearly some amount of emotional instability and obsessive behavior even before he was framed for rape. As a child he was socially awkward and had obsessive tendencies as shown with the scribbled writing in his yearbook. As an adult he's toned down the socially awkward aspects, but the obsessive and meticulous parts of his personality are ratcheted up, which manifest themselves in the custom-made Valentine's Day cards he sends to his targets (coupled with a box of maggot-infested chocolate in one case), matching up each target's fate with how each insulted him, and going out of his way to murder Dorothy's boyfriend so he could break her and make her easier to frame. And that isn't going into how his drinking problem fits into all this (if it's a problem at all).
When confronted by the killer, Gary, who is trying on Kate's pantyhose, tries to bargain for his life by saying that he is "not well". We don't learn what disorder he has because he gets beaten to death immediately afterward.
Epileptic Trees: After Dorothy was shot dead wearing the killer's costume, a theory arose that Dorothy was also a killer, albeit working independently of Jeremy, and was responsible for the deaths of Campbell, Millie, and Ruthie, who had less involvement with the revenge plot than Shelley, Lily, Paige and Dorothy. Gary and Detective Vaughn are up in the air as to who killed them; the scene with Kate and Adam at the bar points more towards Adam, Vaughn could have been killed by either Jeremy or Dorothy. A deleted scene indicates this was not the intended effect with Dorothy being blindsided by the killer, who put his costume on Dorothy to frame her for his crimes (which explains why Dorothy has a bruise on the left side of her face when she didn't have one while arguing with Kate), but the scene was cut due to apparently being a giveaway.
Hollywood Homely: Dorothy is repeatedly called ugly, with the inference that her younger self is "too ugly" to say no to Jeremy Melton; her boyfriend is a Gold Diggerwho can't get it up. She is a perfectly pretty girl.
Hollywood Pudgy: Also Dorothy, who is repeatedly described as larger than the other girls, but is at most several pounds heavier than them and in no way "fat". This might even be a case in-universe as Kate says that Dorothy was "big-boned", which Dorothy exaggerates as "fat".
Jerkass Woobie: Jeremy Melton/Adam Carr may not be justified in murdering the women who framed him (though some would disagree even with that notion), but you can feel some sympathy for the hell he spent most of his life in, for something he didn't do.
Adam: All I can think is when someone is that lonely or that angry they can learn to hide it. But inside, it never dies. It just stays there. Eats away at you. Until one day, you have to do something about it.
Magnificent Bastard: Jeremy Melton, once a middle school outcast framed for sexual assault and sent to a mental institution, reinvents himself with plastic surgery and takes the name of "Adam Carr", the heroine Kate's troubled love interest. Taking revenge on his tormentors, Jeremy dons a cupid mask, hunting down and murdering those he has a grudge against while also using the chance to endear himself further to Kate, showing a protective side towards her by murdering a man who attempts to steal her underwear. Framing Dorothy, the one who first accused him, for the murders and killing her, Jeremy manages to get away completely with his final vengeance.
Moral Event Horizon: Dorothy crosses it early on when she lures Jeremy under the bleachers, then throws him under the bus when it's convenient by framing him for assaulting her, which becomes the reason why he starts targeting her and her friends for framing him. Later on when she reveals that the assault was a lie, she shows no remorse for ruining his life (even Kate asks why Dorothy would do that to someone) and instead tries to justify her actions by citing how unattractive she was in middle school. After that point, any sympathy to be had for her is gone.
Narm: Lily's blubbering after biting into the maggot-filled chocolate can be a little ridiculous.
Narrowed It Down to the Guy I Recognize: Behind the scenes example; the identity of the killer was still up in the air right up until the casting, but Jamie Blanks realized who the killer was going to be when he heard David Boreanaz was cast.
Paranoia Fuel: Jeremy Melton is a walking version of this trope; the most dangerous part about Jeremy is that he's erased himself from existence and is living under a new identity where he would have access to the circle of friends who framed him. But which one? Underscored by Detective Vaughn:
"I pulled a file photo and I ran some enhancements... but know anybody who looks like this? [changes hair style] Or this? [changes hair color] Brown contacts, blue, green... goatee, beard, mustache? Ten years is a long time. And there's the possibility of plastic surgery. [Kate asks about recent photos] Don't you think we'd be looking at them? The point is, this could be anyone."
Lily receives a box of chocolates... filled with maggots.
The water in Kate's apartment runs out, forcing her to rinse her hair in the toilet. Hope that it's clean.
They Wasted a Perfectly Good Plot: Dorothy being the actual killer or at least one of the two killers, it could have worked well, being that she had motives to commit the murders, and it could have served as a nice twist.
Tear Jerker: The opening is pretty traumatic watching Jeremy being rejected by everyone he asks to dance, and most of them in rather unpleasant ways. Then it gets worse when Dorothy frames him for assaulting her.
Moment of Awesome: Henri Barrow is an ordinary human being in a world of cosmic horrors, and in a Never Mythos short story, where bad things tend to happen to ordinary people. Despite this, Henri manages to wound an Eldritch Abomination and escape, promising to return and bring vengeance onto Helen for what she has done.
Nausea Fuel: The final chapter. To elaborate, thousands of civilians in Bacio who have all fallen under Helen and the Padre's brainwashing powers have a colossal orgy. Keep in mind, the civilians in question are all horribly mutated, deformed abominations who mutilate each other whilst having sex, as demonstrated with Doug and Anita.
Bacio itself is an idyllic little commune with a dark little secret. Enslaved to the lusts of its 'mayor' Helen Valentine, the literal mother to most of the town via her relationship with an eldritch horror known as Il Padre, the people are warped by the Padre's fluids and made to participate in nightmarish orgies of lust and violence. Functioning solely as Helen's kingdom, Bacio is one of the most nightmarish places in all the Never mythos.
Helen Valentine herself is an unbelievably disturbing villain, even in a world with Lucia, Vladik Cardinous and Nyarlathotep himself. A simple human woman who's lived for centuries, Helen produces children to use them as fodder in her twisted little revels, combining sex and violence solely so she can savor the 'pain' of love. It says a lot that between her and Il Padre, Helen easily comes off as the most monstrous of the duo.
