Direct quote 1997
“You've got to have an entertaining side, like a Hollywood action movie. It's got to be fun as a game, and the intrigue of the world should gradually pull you in more and more, and by the ending credits you should be left with something to think about.”
What it documents
In 1997 Kojima said he wanted to show, in a realistic way, the fear and dread of war, but that pushing that to the forefront would suck the fun out of the game; it has to have an entertaining side like a Hollywood action movie, be fun as a game, and the intrigue of the world should gradually pull the player in more and more so that by the ending credits they are left with something to think about.
Source
shmuplations.com; MGS development interview in Famitsu Weekly (1997), unofficial English translation. View source ↗
“Yeah, you could say I want to show, in a realistic way, the fear and dread of war. It would suck the fun out of the game if I pushed that to the forefront, though.”