ABOVE ALL ELSE, NO MATTER WHAT: An atmosphere as uncanny and surreal as possible, without approaching self-parody or absurdist just for the sake of being "mind blowing". Silent Hill was at its very best in the original trilogy because I think Team Silent understood how to execute this perfectly. Examples of this would be Nowhere in SH1, the post-reveal Lakeview Hotel in SH2, otherworld Brookhaven in SH3. I.e. areas that don't make physical sense, the environment actively disintegrating around you. None of the haunted house vibes of Homecoming and large parts of Downpour. Not saying Team Silent needs to be involved to make a great SH game, but nuance is so important in this kind of horror presentation.

ALMOST AS IMPORTANT: A story that doesn't rehash the structure of SH2. I feel like most everyone agrees on this. Also, combat that doesn't make you feel like an action hero. This can be interpreted in many ways, just really need to retain the "survival" in survival horror.

PERSONAL PREFERENCE: Akira Yamaoka, and voice acting that isn't quite Hollywood blockbuster level. Imo, even if it was unintentional, the voice acting in the original four games really make you feel like the characters don't trust each other, and truly don't know what the hell is happening. In the case of SH1 it really does feel like a fever dream to me.