* {{Applicability}}: Some of the dialogue during [[spoiler:Booker and Millie’s kiss scene]] more than a little resembles a conversation between a trans person coming out to a cis love interest, particularly [[spoiler:the part where Booker tells Millie (who is quite literally a girl trapped in a man’s body) “You’re still Millie to me.”]] Considering both Michael Kennedy and Christopher Landon are gay, the similarity is very likely intentional.
* BaseBreakingCharacter: Josh, particularly due to a line at the beginning of the movie where he casually admits to being okay with [[DoubleStandardRapeMaleOnMale date-raping drunk straight boys at parties]] in order to make them realize they're "fluid." Some see the line as [[CrossesTheLineTwice line-crossingly]] fitting for a horny immature teenager and believe [[CharacterDevelopment he gets better]] as the movie goes on, not to mention having far funnier lines later on in the film, while others dislike him because of those concerning lines. Not helped by the fact it essentially serves as his EstablishingCharacterMoment.
* CatharsisFactor:
** Despite some [[DisproportionateRetribution probably not deserving]] [[CruelAndUnusualDeath horrible deaths]] at the hands of an evil sadist, seeing [[spoiler:Mr. Bernardi]] and the others who attributed to Millie’s misery suffer while getting brutally killed still feels karmically enjoyable. Millie while possessing the Butcher getting non-lethal revenge on the boy who constantly barked at her also counts.
** [[spoiler:Millie [[KarmicDeath destroying the Butcher]] [[ImpaledWithExtremePrejudice with the table leg]] right at the end of the movie]] is fittingly enjoyable as [[spoiler:she not only gets the confidence to assert her own physical and mental strength, but brings down an unrepentant mass murderer in the bargain.]]
* CompleteMonster: [[SerialKiller The Blissfield Butcher]] is a sinister and ruthless middle-aged man targeting teenagers for [[ForTheEvulz nothing but his own desire to cause death at every turn]]. TheButcher, having possibly been at large for years, breaks into a teen girl's house and savagely murders her and three of her friends without a second thought and then attempts to kill Millie Kessler the next night. After accidentally [[FreakyFridayFlip switching bodies with Millie]], the Butcher then takes advantage throughout the day by [[CruelAndUnusualDeath graphically murdering]] five other teenagers and wood shop teacher Mr. Bernardi while trying to get Millie caught by police while in his body. He also taunts Millie about being weak and pathetic and tries to make the switch permanent as well before eventually returning to his body and then trying to go after Millie one last time at the film's conclusion.
* HarsherInHindsight: Char holding Nyla at gunpoint after so many [[PoliceBrutality incidents of police officers]] shooting innocent people of color in 2020, the year of the movie's release.
* SugarWiki/HeartwarmingMoments: Despite the {{Squick}} factor for some fans, [[spoiler:Booker kissing Millie while she's in the Blissfield Butcher's body shows that he loves her for who she is on the inside.]] The moment is [[https://news.yahoo.com/vince-vaughns-same-sex-kiss-200100968.html intentionally played as a true love scene,]] and not [[PlayedForLaughs for laughs]]. Noticeably, as mentioned above, [[spoiler: it's not a spur-of-the-moment thing but Booker is well aware that Millie is in a man's body, it just doesn't matter to him]].
* HollywoodHomely: Millie, who despite looking like a gorgeous blonde model is treated as a pariah at her school (Justified as she's presented as shy and dealing with her grief about the death of her father).
* {{Moe}}: Millie. She's a ShrinkingViolet with some cute {{Character Tic}}s, gets harshly bullied for being the school's mascot, a job that she seems to care about, and is too shy to tell a LovableJock about her crush on him. And that's before her FreakyFridayFlip with a middle-aged man adds a new level of awkwardness to everything she does.
* MoralEventHorizon: The Butcher crosses it instantly by viciously murdering four innocent teenagers in [[EstablishingCharacterMoment the very beginning of the movie]].
* OneSceneWonder:
** Ginny, the opening scene victim who gets some MetaGuy lines and almost escapes from the Butcher.
** The Spanish teacher who translates the inscription on the dagger and sternly lectures Josh for being unable to do so himself despite taking her class.
* {{Squick}}: [[spoiler:Booker and Millie kissing while she’s still in the body of the Blissfield Butcher.]] This scene is a rare overlap between squicky and [[SugarWiki/HeartwarmingMoments heartwarming]] (see above).
* TheWoobie: Poor Millie went through a lot. Her father died, she is bullied by some students, even a teacher, and then a serial killer attacks her. To make things worse for the girl she actually switches bodies with said serial killer, causing her to get chased by the police, including her own sister and temporarily be put in jail in his place. The girl deserves a hug for everything that happened to her.