First of all, del Toro is pretty much the ONLY fellow I'd trust with a full-out Lovecraftian Horror movie and bringing on Cameron could only make things better. The fact that anyone balked at this project being "R" rated is insane - there are tons of horror movies released with R ratings that either "hyper realistic shaky cam" or "forgettable slasher" and nobody bats an eye. If the project ever gets off the ground and is uncompromising as I hope Del Toro will be, I'll be watching it at the midnight premiere.
Next, to address Scott Pilgrim. Anyone who's seen the movie, I urge you to read the graphic novels upon which it was based. I'll say that it simply isn't a very robust movie adaptation of the novels. Don't get me wrong, the aesthetics and whatnot are fine more or less, but it didn't convey the gravitas and key points of the film. Also, you probably noticed that the entire movie led up to ending with a Scott+Knives relationship - This was how the movie was originally shot, but was changed when the graphic novel's artist ended the comic differently. Thus, the entire ending was really anemic - it didn't use the momentum of the film to create a conclusion, nor did it undertake and replicate the comic book's ending which was much deeper and more expository.
That said, I've seen a lot of criticism about the movie version of Scott Pilgrim that I feel is unwarranted, but generally unavoidable. Some of this transitions to the much deeper comic as well. First all the "video game" stuff - I didn't find it forced, but realize its a simple storytelling mechanic and metaphor. Scott's Toronto operates under video game physics, but its important to note how banal it is to all involved - its nothing special to be able to perform "video game magic" in Scott's world. It is important to note that the entire Scott Pilgrim story could have been told without any video-game combat, "awkward-chic" puns, and "indie/hipster" set. If it was, many would call it a chick flick, or at least a relationship based character study. Without the video-game battle metaphors, many of those that read/watched would have never sought out a similar study.
Scott Pilgrim vs The World is a study in Western 20-30something relationships and maturity. Sadly lots of the "big reveals" in the end of the comic were not present or weak in the movie. Scott and Ramona both act as many young people do with brash impetuousness, rarely considering the feelings of others or anything beyond their own whims. As the story progresses and they both learn to take responsibility for their past and decide what they want for the future, this contrasts against Gideon's paradigm. Without trying to give away too many spoilers, its really important that one read the complete graphic novel to see the full range the author intended. Its actually a fairly sophisticated investigation into relationships of today's youth, far more so then many that come to mind in recent years.
This is one reason that the whole "Twilight for Boys" laughable take on it (originally pronounced by a Fox News reviewer , no less) - Twilight can be interpreted as anything from a mormon morality fable/acceptable "Porn", to a MarySue-filled fantasy fulfillment. Scott Pilgrim is the antithesis of this, as its primary underlying theme is one of maturity and taking responsibility for one's actions. Scott, despite his powers, is not a "self-insert" hero. Depending on the media he's more awkward (movie, as per Cera's typical portrayal), stupidly oblivious and in some cases a downright jerk (move visible in the comics). All his powers don't bring him happiness until he learns to gain some new perspective and change his interactions with others. The lead female, "Ramona" doesn't simply fall into his lap because he's there and in fact has some considerable flaws of her own and undertakes a journey entwined with but different from Scott. Characters on the periphery give some insight into the main themes and have stories of their own, which were mostly underserved in the film. Anyone who sees Scott Pilgrim as a primary "video game fighting action movie" is missing the point.
Ultimately, this is the problem with the story and medium. When brought to film, especially with all the cuts and adaptations made, the video game aesthetic basically summoned a much larger demographic to the theater. The very core audience for the film is likely the same 20s and 30s portrayed within, but this brings an important issue to light. The underlying story about maturity and relationships is only accessible to those viewers who have already made strides in that area themselves. If Scott Pilgrim himself was to have seen the film, as the character he was during the start of the comic, he probably wouldn't have thought it was much more than some video-game shiny action and might even find it bland. Lots of young people have the attitudes and behaviors of the story's characters, but I find it disconcerting that older reviewers seem to have difficulty grasping these concepts as well. Perhaps they are simply biased by the video-game retro trappings and can't or don't wish to see what's under them, but sadly there are many "grown adults" who maintain the same kind of oblivious selfishness all their lives when it comes to relationships, thus compounding their inability to understand the film's message.
Putting out a movie like this, especially lacking the robust story elements present in the comic, was really asking for trouble. Marketing it solely on its retro VG aesthetic and trying to make it less complex and more accessible was not, in my opinion, the best decision for the medium. However, even diluted as it is Scott Pilgrim is a "good" movie, but really could have been "great" had there been no compromises made and the mythos fully fleshed out. There still would have been the problem of viewers not "getting it", but perhaps if all the exposition was present the themes would be easier to absorb. Really, the source material deserved more than was given on screen, and even the movie deserved to stand on its own merits sans those without the capacity for understanding the themes or those with inherent biases against the aesthetic passing judgment.
This is plain depressing 
