- Alternative Character Interpretation: The alternate timeline version of Danielle is less openly obnoxious than her prime timeline counterpart. She even provides significant help for Tree in distracting Dean Bronson. On the other hand she is still seriously vapid and cheating on Carter; it's also implied she's dating him so he'll do her schoolwork for her. It is open to interpretation whether she is simply pretending to be a better person or is genuinely slightly less awful than her counterpart, if still really self absorbed.
- Complete Monster: Dr. Greg Butler of the other dimension contains the same arrogance as his main counterpart, but crosses the threshold into evil here as a spree killer. Like in the primary dimension, he is a charming if smarmy professor cheating on his loving but aging wife with his students. In the other dimension, when his wife finds out about his affair with Lori, he plans to kill the latter and cover everything up; the constant is him releasing John Tombs to use as a scapegoat, only to carry on where he left off and kill anyone in the vicinity when Tree kills Tombs. In the loops, Butler has killed Tree, Lori, Carter and is responsible for the deaths of two others, with a news report implying that at least one murder spree is still unfolding, and a cop being one of the victims. When finally confronted, Butler reveals his wife is in on it with him, only to murder her as well now that she's no longer useful, before trying to kill Tree a final time.
- It's the Same, Now It Sucks!: One of the biggest criticisms of the film is that it feels derivative of its predecessor.
- Moral Event Horizon: If the alternate timeline version of Gregory Butler didn't cross it already by trying to kill Lori and all witnesses to cover up his affair, killing his wife for no reason beyond being bored with her certainly caused him to.
- They Changed It, Now It Sucks!: Unlike the first film, the sequel is more of a sci-fi adventure with its horror elements almost an afterthought as the plot goes on, disappointing some who enjoyed the genre elements of the first film and wanted to see more.
- They Wasted a Perfectly Good Plot: The opening scene with Ryan as the protagonist, or exploring the idea of two of the same people existing in the same dimension (especially one trying to kill the other), could have made for a compelling plot all on its own, but said plot is resolved within minutes in favor of Tree doing a rerun of the first film with the details changed.
YMMV / Happy Death Day 2U