well the answer is obvious, the majority of a game is to be measured by the fastest possible gameplay lenght.
no, a speedrun does NOT count. its not how long a speedrunner plays a game but how long the general gameplay is.
Wait what? Are you saying the "obvious" answer is incorrect?
I also get the idea you haven't played Heavy Rain, and never got really into any Metal Gear games (
edit: although I can't speak for the original Metal Gear on the NES if that's what you mean).