As I said frames per second in movies is not the same as frames per second in games.
There has been discussions about this before, and there's no need to drag this thread there again.
You see, in games for example a framerate of 18 fps is stuttery and skippy as hell, whereas in cinema that framerate would still seem pretty fluid.
...hint: motion blurring
One might be satisfied with Halo framerates next gen, but I will not. The fluidity like can be witnessed in games Gran Turismo 3-4, Ratchet & Clank 1-3 does make a huge difference visually and gameplaywise compared to those with less fluid and constant framerates.