https://www.cnet.com/news/uncharteds-developers-just-revealed-a-bizarre-secret-about-nathan-drake/

Uncharted is a cinematic action-adventure video game series where you climb things, shoot things and solve puzzles. It is a game where Nathan Drake, the protagonist you play as, gets shot at.

If you've ever played a video game that involves guns, you're likely aware that the screen filling with red is an easy way for the game developers to say "YOU ARE TAKING DAMAGE!"