Let the Right One In (2008)

Continuity mistake: When Oskar shows his Rubik's Cube to Eli and explains how it works, one side is all white except one square, which differs from being red vs. blue between shots.

Other mistake: When Oskar finds the solved Rubik's Cube it cuts to a shot of Eli sleeping, wearing a large shirt/dress. However, this shirt/dress is the same one that she takes from Oskar's mother's closet later on in the movie and therefore, she wouldn't have it yet.

Continuity mistake: When Oskar intercepts Lacke's plan to kill Eli in the bathtub, Eli kills Lacke and drinks some of his blood, leaving some blood on her lips. She then kisses Oskar, which in turn leaves some blood on his lips. In the cut right after that the blood is gone from his lips. Later on it appears again, when he tastes it with his tongue.

Trivia: At the end of the movie when Oskar is traveling on the train with Eli inside the trunk, and they are tapping Morse Code on the trunk's lid, they are spelling out "P-U-S-S," which means "small kiss" in Swedish.

Eli: I'm twelve. But I've been twelve for a long time.

Oskar: Are you a vampire?
Eli: I live off blood... Yes.
Oskar: Are you... dead?
Eli: No. Can't you tell?
Oskar: But... Are you old?
Eli: I'm twelve. But I've been twelve for a long time.

Eli: Oskar... Do you like me?
Oskar: Yeah, a lot.
Eli: If I wasn't a girl... would you like me anyway?
Oskar: I suppose so.