My vote goes to either Vagrant Story or Parasite Eve, both by SquareSoft. Both games are pretty short and I could see their stories being adapted into a 2 hour film without having to change all that much. Yeah I know Parasite Eve was originally a book and that book had a movie adaption, but I'm talking about the game's story here.
That would be great! The closest we have are the Musou games, but I'm not a fan of that style of gameplay.