In a recently discovered older interview from the late 90s, Kojima reveals that he considered leaving Konami at the beginning of his career. This was due to a lack of support internally and a feeling that no one was listening to him or taking his concept seriously. This came to a head when he tried to pitch Metal Gear to his bosses, but was rebuffed.
I was still a new planner at Konami, so I guess no one was inclined to listen to what I had to say…
The turning point came when Kojima introduced the now iconic exclamation mark symbol above enemies’ heads. This seemingly simple visual cue effectively demonstrated the game’s potential and convinced Konami’s veterans that Kojima’s game idea had potential after all. After which they completely changed their minds.
When they saw the exclamation mark pop up, that sold them on the concept. They all changed their tune then: ‘This is gonna work!’
The rest is, as they say, history, and it’s hard to imagine a world without Metal Gear.