Things changed thus far:
-Dynamic lighting. Walls will now create shadows actively depending on the location of the player (you'll see it in-game, it works great).
-Ayumi's flashlight completely changed. Now it brightens an area around her instead of pointing to a tiny cone in front of her.
-New font used. This should improve the overall atmosphere of the game.
-Minor map changes (for example in the cafeteria, there is now a candle that makes the location of the patrolling crawler obvious, which in the past had caused people to die to not being seen).
-Some dialogues changed, especially towards the end-game, so that they sound more natural. In the current version for example, it makes no sense for Ayumi to be angry at Liturgy 9 for following the King's advice. In the new version she will just be confused and it will be left to the player to figure out what Liturgy is saying.
-Many of Ayumi's previous descriptions replaced with sound effects.
-The club is now locked until the player finds Suzumi's card. I noticed in youtube playthroughs that it's the first place people visit even though it's intended to be visited later.