Catharsis Factor: The majority of people who get killed by Angela are all the most despicable human beings who bear resemblance to some realistic people that plague society.
Designated Villain: Angela really comes across as this. The campers surrounding her are all nothing but jerkass bullies who pick on her at every turn as the camp councilors stand by and laugh at their "innocent fun". One can't help but feel a little satisfied when she offs all the Hate Sink characters and cheer her on for rewarding their cruelty towards her with brutal deaths.
Ethnic Scrappy: Riff is an African-American gangbanger who lives for nothing but causing trouble, has a Hair-Trigger Temper, assaults others for run, and has no redeeming qualities at all. He's one of the most disliked characters in-universe and out of universe for these exact reasons. Don't worry, Angela kills him.
Paranoia Fuel: Angela is able to easily kill Maria in crowded street in public by simply tricking her into entering a dark alley by running her over with a semi-truck. After killing her, she steals Maria's identity to impersonate her while nobody knows of the real Maria's disappearance.
Unintentionally Sympathetic: Maria, the girl killed in the beginning, has gained some sympathy due to her living a troubled life, having a strained relationship with her parents, and attempt to change her life by attending summer camp only to be cruelly killed by Angela so the Serial Killer can steal her identity. Made all the more worse since nobody is aware of her true demise.
Unintentionally Unsympathetic: Marcia losses all likability when she reveals to Tony that she's had a boyfriend all along and assaults Angela after the killer spared her life.
What An Idiot: When Maria's running for her life from a semi-truck trying to run her over, she has the option to run down a crowded street full of people to help her or run down a dark alleyway where nobody can see her. She chose poorly.