First, if you haven't figured it out, this is a comic book film with Michael Cera as the super hero. In fact, the new Captain America (Chris Evans) and the latest Superman (Brandon Routh) are in this film. While it's unlike most comic book movies, the above casting is more than a coincidence, I'm guessing it's probably partly a nod to the fact this film is a comic book film.
Second, the film has a TON of references to old school Nintendo and even Atari games. Even if you didn't own an original Nintendo (me) and consider yourself much of a gamer (me), you'll still get many of these references if you're between 25-40. I'm guessing before the week is out, some video game geek will post on their blog ALL of the video game references to this game.
That being said, this film would fall flat if it wasn't well done. This film is well done. The script is hilarious. You'll be laughing at this film at least every couple of minutes. Also, I mentioned above that Michael Cera is a comic Book "hero." That point alone is hilarious.
As far as the acting goes, overall, the movie is well-done. The seven evil exes are pretty great. A couple fall a little flat, but not enough that it's detrimental to the show. Brandon Routh's character is great as is Chris Evans. The supporting cast? Kieran Culkin is a highlight and many of the laughs revolve around him as Scott's gay roommate. Anna Kendrick as Scott's sister has some great laughs, as does a couple of the band members (Johnny Simmons and Kim Pine). Scott's love interest Knives Chau is a highlight of the film. She acts well and steals nearly every scene she's in. The only disappointment in the cast was Mary Elizabeth Winstead as Ramona Flowers. She looks kick-grass, and I found myself wanting her hair, but her acting falls flat.
As far as Michael Cera goes? Last Summer I found myself really sick of Michael Cera. He plays the same character over and over and it was getting really old. However, even for this die hard Arrested Development fan, I found myself really surprised by Michael Cera's acting chops in this role. Granted, he's playing the same character yet again, but he does it really, really well. He breathes life in a character that could be so one dimensional, and yet somehow is hilarious. There's several moments that really stood out to me (One of the very first scenes with his band when he's talking about what he does with his girl friend), another scene where his girl-friend tells him about the exes and he's fixated on the fact he has a girlfriend who will make out on him and not the battle itself) and just the little things.
Anyway, go see this film if any of the above appeals to you. I did think the comic-book action subtitles got a little old, but overall, this film is great.
Even though this film failed at the box office, I tell ya-this is still going to be a cult classic, and a generation-defining film.