
Not to turn this Patreon into the Resivick channel, but something else occurred to me while playing Capcom's Haunted House. Both of its main-characters, Leon & Claire, will not only react physically to whatever's happening on screen, but vocally.
This is something I've notice becoming more and more prominent in games. Battlefield 1 has your soldiers scream when charging, bayonet at the ready. Insurgency: Sandstorm has tons of extra character lines. Rising Storm 2 even had characters panicking in tense situations, such as reloading while enemies are right around the corner.
It's a detail that personally, I've been really enjoying for the most part. Similar to how Need for Speed: Shift ushered in a new wave of developers viewing the cockpit as controlling a driver rather than a vehicle, these voice-lines and reactions do give a certain novelty to controlling somebody. Rather than being a silent, self-insert, far more skilled version of myself, I'm controlling somebody in that world, who themselves behave and react in a believable manner.

However, RE2 might be the weakest execution of this concept, as it disconnected me on occasion, rather than being immerse. It's rather awkward to be standing completely still, aiming a gun with the steadiness of a Navy SEAL, and shooting your 158th Zombie, and hear your character shout "What the hell!?"
And that probably lends to the reason why, despite more games attempting it, most still don't. Because should these lines suffer from poor direction, mismanagement of placement, or even just gameplay changes, you're opening yet another door for players to be pulled out of the experience, all in the name of immersion, but at the same time...

Can't that be said for everything? Great graphics can expose more flaws in your animations. Seamless scripting could make setpieces more overt. The better you do something, the more areas you have to maintain that same quality. It's part of the job, challenge, and reward of creation.
After all, these lines aren't detrimental to RE2's enjoyment, and should Capcom continue with this concept in future games, hopefully they apply the lessons learned to make them even better in the sequel.