A movie so bad Final Fantasy fans wouldn't even go see it? And, if you are talking about Advent Children, a movie that was just an hour and a half cutscene?
While I actually enjoyed watching Advent Children... this made me
Yes, I admit I enjoyed it. Despite the idiotic plot, unbelieveable action and ultra-ultra-ULTRA-cheesy dialogue and story.
FF:The Spirits Within was halfway decent, hamstrung by some unbelievable plot devices, terrible facial animation (which was supposedly going to be its strongest feature) and a weak story.
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While I disagree with Duke, on the premise that no generalization can be true... I can't honestly think of a single game-movie conversion that actually produced a movie worth watching, except on a beer-and-chips night when the cable is out. Not a single one...
I've looked up the online lists of video-games to movies... guess what? I've watched most of them, and all of them suck. The only halfway decent ones were maybe Tomb Raider I, which was mediocre except for the fight scenes... and Mortal Kombat (the first movie only) which was a movie
about fight scenes... oh... and maybe Resident Evil I, just for the babe-age. Still all beer and chips fare, and not anything I'd actually pay money to watch if I had to go watch them again.
And don't get me started about movies that look like video games... the platform scenes in Minority Report and Star Wars Episode II were so laughable that I almost walked out of the movie house when I saw them. Honestly... who thinks up this stuff?
Comic books? That's another matter, entirely. Some comic books actually have a story... too bad that's a rarity, nowadays, too.
But movie-to-game... there have been some bright points there... whie most movie-based games have been unutterably dreary, there have been a few Star Wars titles worth playing... and James Bond GoldenEye on the N64 was one of the best console shooters of all time...
Still doesn't make most of these new movie-based videogames anything more than expensive doorstops, though.

I've played some pretty crap-tacular ones. I'd say the number of good movie-based video games is about one in one hundred... and since they seem to make about a hundred movie-based games a year, chances are at least one of them will be good.