1. Michael Cera was the first and only person in mind for the role of Scott Pilgrim, after Edgar Wright saw him in Arrested Development.
2. Mary Elizabeth Winstead (Ramona Flowers) is from North Carolina, the same place Ramona is from in the books.
3. Mae Whitman, who plays an evil ex, was in Arrested Development as the girlfriend of Michael Cera's character.
4. Scott Pilgrim's name comes from a song of the same name by the band Plumtree.
5. Before the cast started on the movie, they were given a list of 10 secret things about their characters.
6. One of those was that Julie Powers had a massive crush on Scott during college.
7. At the point when work on the film began, only two of the books had been written.
8. Because of this, some lines from the movie actually make it into later books.
9. The title sequence idea didn't come about until late in the production process, after it was suggested by Quentin Tarantino.
10. Each cast member has a symbol relating to their character in the opening credits; coffee stains for Anna Kendrick, black boxes for Aubrey Plaza, etc.
11. Edgar Wright didn't want any British actors for his first North American film, and didn't realise Satya Bhabha (Matthew Patel) was British until after he'd got the role.
12. In fact, it turns out Satya grew up near where the director lived.
13. Though part of the film is about Scott's being several years older than Knives Chau, in real life Ellen Wong is actually three years older than Michael Cera.
14. Similarly, Anna Kendrick is older than Michael Cera but plays his younger sister.
15. Ellen Wong auditioned three times for the role of Knives, and got the director's attention after he discovered she was a green belt in taekwondo.
16. It was also her film debut.
17. Johnny Simmons (Young Neil) got offered the role over Facebook.
18. All the exes have references to their numbers throughout the film (Todd Ingram, the third evil ex, wears a shirt with three stripes on it and the number 3 on the front).
19. Similarly, as he's not an evil ex, Scott wears a T-shirt with zero on it and drinks Coke Zero because that's his number.
20. The actors playing the Vegan Police were the only people in the movie aged over 30 at the time it was made.
21. Bill Hader does all the voiceovers for the film, for example when Scott earns the power of self-respect.
22. Beck wrote all of the Sex Bob-omb songs in the movie.
23. Michael Cera could already play some bass before starting.
24. Those who couldn't already play instruments had to actually learn them.
25. The Lucas Lee stunt doubles are actual stunt performers who double for Chris Evans.
26. Edgar Wright wrote a letter to Nintendo for permission to use a song from The Legend Of Zelda, in which he called the game's music "nursery rhymes to a generation".
27. The doors with a star on them that Ramona travels through are a reference to the Mario games.
28. The original ending featured Gideon turning into a robot but was scrapped.
29. In the scene where Scott opens the door to Ramona, it took over 30 takes for Michael Cera to throw the package over his shoulder and straight into the bin.
30. Edgar Wright encouraged the actors to not blink during takes, to give it the feel of anime.
31. There's an alternate ending in which Scott ends up with Knives.