This movie is from Edgar Wright, and if you've seen Spaced, Shaun of the Dead, or Hot Fuzz, you have some idea what to expect. The movie is full of pop culture references.
The movie is basically set up like a video game. The hero, Scott Pilgrim (Michael Cera) likes this girl. In order to date her, he will have to defeat her 7 evil exes. Kind of like a video game where you have to defeat a boss at the end of each level.
The rules of physics do not apply in this movie. Each time he fights an evil ex, suddenly everyone can fly and has powers. The funniest part is when he defeats an enemy, they vanish and leave coins behind.
Some random things I liked in the movie:
The Universal logo in 8-bit Nintendo graphics and sound.
Brandon Routh's vegan powers, how he loses them, and what happens then (the Vegan Police!).
When Routh punches a girl, he punches the highlights out of her hair.
Everything Kieran Culkin says.
The Seinfeld bit.
Alison Pill (the drummer of Pilgrim's band, and one of his exes).
My only complaint about the movie is it's too long. I was ready for it to be over with about 20 minutes to go. They did a good job of making each battle with an ex different, but by the time he got to the final one, I was about done.