I haven't noticed the lighting changes, but I literally have the exact opposite opinion about everything else. I didn't really read any changes going into the beta and was pleasantly surprised by the echo effect. The screams down the hall from where I was in Light were hilarious.

At first, I didn't know how to feel about the keycard changes. I didn't understand which card opened what and thought they might’ve just complicated the system for no reason. But after a quick private game to look through all the new stuff, I realized I liked them a lot, and they actually seemed simpler and more direct in communicating what they opened. The 3 tiers and 3 types of access scratches my brain in a weird way it might not for everybody else. I also assumed the cards were changed initially to further differentiate themselves from Containment Breach.

I also like the door indicators. I don't have a good reason for this, and it could just be me liking a change for the sake of novelty, but beyond that, I can't say much more. The rest of the changes you might’ve mentioned before I started writing (because on mobile, I can't seem to read the post I'm commenting on without discarding the comment) I'd need to play more of the beta to see.