Link: https://www.pcgamer.com/games/resident-evil/when-capcom-brought-in-a-professional-screenwriter-for-the-original-resident-evil-2-it-was-his-idea-to-fully-embrace-the-series-goofy-puzzles-well-just-have-to-make-the-police-chief-a-weirdo/

In an alternate timeline, Resident Evil could've become a lot more serious.

As long as everything was consistent, it would appear real.

That's very much the foundation of every good story ever told.

Every work of fiction is allowed one premise, one "big lie"

Could range from "vampires are real" to "the chef is controlled by a talking rat in his hat" but the audience will accept it without question as long as everything else is logically consistent and stems from that premise.

In RE2, making the police chief an absolute nutcase is it, and everything works from that.

That's why stories with ridiculous premises can still feel real and solid, while stories with realistic settings can fall apart as ridiculous and unbelievable - when they make the mistake of lots of immersion-shattering small lies, instead of the one big lie which is allowed.

I'd say one big inconsistency can be a premise, a second big inconsistency can be a twist, but they do have to feel intentional and being big makes them feel intentional. Lots of small inconsistencies throughout won't feel like they're intentional, they'll just feel like poor planning and lazy writing.