One of Us: With a Shout-Out list stuffed to the brim with video game references, Brian Lee O'Malley is truly one of us (and by that extent, so is Scott).
Teasing Creator: O'Malley has said on multiple occasions, that, although the Scott Pilgrim series is done, he's not done with these characters, and has implied several times he may make more books in the same universe, though not necessarily with Scott as the protagonist.
Write Who You Know: By O'Malley's own admission, Scott's life is based on the lives of himself, his wife, and his peers when he was a young twentysomething. He was in a garage band, obsessed with video games, and fell in love with (and eventually married) an American woman who had several ex-boyfriends whom he jokingly thought were all in some kind of League together.
Comeau is based on and named after a friend of O'Malley's.
When Lynette punched the highlights out of Knives' hair, she was so badly (and socially) injured that a doctor said she will never be cool again.
Another is when Wallace and Kim dance in the beach at book four. Kim was smiling.
The third volume's cover art was going to be the main characters standing in the middle of Toronto, the fourth volume's cover art was going to feature Lisa Miller winking in a blue fluffy background, and the fifth volume's cover art was going to be Ramona in a pink sweater looking down at the ground on an empty white background.
The amp vs amp battle with the Katayanagi Twins in the movie was supposedly based on an earlier draft of volume 5.
Young Neil was originally going to be 9 years old.
Almost certainly a coincidence, Scott is the exact same age as Paramore's former guitarist, Josh Farro. The two have the same birth year (taking into account the implied setting of 2011 for the comic Scott would be born in 1987) and Scott's birthday (9/27) is two days before Farro's (9/29).
Maybe Scott should worry about Wallace peeing all over him, seeing as he shares a bed with him.* No, this isn't confusing Kieran Culkin with his brother Macauley. Kieran played Kevin McCallister's cousin Fuller, who was known to wet the bed.
The DVD contains storyboards and concept art for a very different conclusion to the final battle. Two words: Mecha Gideon
Ramona was originally supposed to fight Gideon during the final battle, but the choreographer determined that having four people fighting in a small arena suspended high in the air was too dangerous, so Ramona spends most of the fight on the sidelines.
Word of Saint Paul: In commentary, Aubrey Plaza, who plays Julie, asserted that her character had (and possibly has) an unrequited crush on Scott, which is why she's so hostile to him. While Bryan Lee O'Malley, the creator of the original Scott Pilgrim comics, responded that Plaza was "making shit up", Edgar Wright, the director of the film adaptation, supported this view.
An odd fact mentioned in the making-of documentary. The studio originally wanted the film to be shot in New York, Edgar Wright had to insist on using Toronto. One of the producers mentioned that normally, anything that identifies Toronto as Toronto has to be avoided when normally shooting a movie in Toronto, but here they could go nuts in shooting these locales. And they did.
Ellen Wong, the actress who plays Knives, is actually a few years older than Michael Cera.
This movie has caused Michael Cera to turn himself into a real life example of Crouching Moron, Hidden Badass. He underwent martial arts training for the film's fight scenes and enjoyed it so much he started training for real. He still looks like a complete wimp, but nowadays he's a complete wimp with a black belt.