RE had a really immersive setting which was made even greater by the soundtrack and the style of the graphics (in particular I mean the pre-rendered environments), also the puzzles were weird and also contributed to the overall weird feeling of the game, as in stuff like "There is an engraving at the base of the maiden's statue in the shape of a hexagon", the puzzles were simple enough but did the trick, and the fact that you need the Ribbons and Typewriter to save-game added that sense of unique-ness, it's also true that horror doesn't work if the player can save-scum through any encounter.
When I think about old RE, I think of the feelings tracks like this evoke:
https://www.youtube.com/watch?v=v7JECkVzuq0
That special feel and design was completely and utterly lost when RE became full-3D action game, and it's a shame because it really was a special type of game.