There is a reason anime is anime, and live action movies are live action movies. They are different genres dear forum, and to expect the sine qua non of either to shift effortlessly between media is overly optimistic. Ergo, most movies based on video games, or anime--will suck ass. I'm going to highlight three challenges that anyone aspiring to craft a successful film out of anime will face.

First, any animovie will face the challenge of what I'd like to call "condensation." Most anime comes in the form of weekly episodes, with 13 or 26 episodes per season. Feature films on the other hand are 1-3 hour stand-alone items. So this first challenge you would have is one of presenting material in a way that maintains the spirit of the original series without limiting your appeal to the uninitiated. Unless the anime you're using is a cultural phenomenon as large and persistent as Star Trek, you cannot count on the name to sell tickets. Admittedly this may be less of a problem in Japan.

Second, you face a problem of continuity. Bleach: Memories of Nobody is a good example of this problem. Since Bleach is still being written by Kubo, nothing meaningful in terms of the series itself can happen in the movie. Imagine Lord of the Rings as a hit TV series and then a movie. They could NEVER throw the ring into Mount Doom and destroy Sauron since doing so would end a hit TV show and put a good many people out of work.

Third, you face the shiny factor. I will say it here and now, there is no way to preserve the feel of anime if you go live action. It will never, ever feel "right." This problem may be ameliorated, depending on the series you use, but part of the fundamental appeal of anime I think, is that it is unreality. If you try to take it too close to reality things will just feel creepy or farcical.

Imagine live action Pokemon for a second. Pikachu shocks a Pidgy. Suddenly you realize you're enjoying the equivalent of a Dogfight and possibly one of the worst examples of animal cruelty ever.

Consider Naruto moved to a live action context. Wait--they're using child-soldiers and training them to be hired killers from birth? Konoha is pretty damn evil. Yugioh: They're killing each other over a friggin CARD GAME. Then there's the Melancholy of Haruhi Suzumiya. God is a Japanese schoolgirl who loves to pretty much rape vulnerable classmates? Creepy. Sailor Moon? Creepy. Love Hina? CREEPY. Ranma 1/2? Disturbing! Neon Genesis Evangelion? Yay. Gendo the p*d*p****!

Basically the closer to normal an anime series seems to get, the more of a psychological buffer we need to accept it as being entertaining. Maybe this is why Otaku can get so creepy. In a feature film this buffer is generally not there which is why anime will not work as a movie.