It did flop, big time. The reason it did was because it wasnt a game sequel. Everybody was expecting a movie based from one of their games (like Advent Children) instead they got a completly different story altogether.Spirits Within flopped from what i heard
Now, Ive heard rumors of a Metroid movie (to be directed by John Woo), but games I would like to see as a movie would be Xeno gears/saga or a Soul calibur movie.
The xeno games simply because their stories are amazing and the sci-fi theme would rock.
Soul Calibur, simply to see the fights and how the weapons would look (ok ok, also how the girls would look )