Atmosphere and music is certainly part of it. If I had to focus on one aspect, I'd say world interactivity; stuff stays where you put it, you can collect chests to organize your loot, set up camp where you want, etc. That extends to the character and quest design, as well. Playing the demo before the game was released, the first thing I noticed was that there were actual quests and a story, not just straight hack and slash. I had previously gotten bored with Diablo 2, and didn't finish (as with the first one). Exploring Aleroth I killed some rabbits for their meat and experience points, looted houses, did some non-combat quests, found stuff under piles of other stuff, etc before entering the catacombs and getting into the spooky atmosphere.
Trying the demo for some action RPG awhile after finishing DD, I was quite disappointed I could walk into an area with a dozen chests, yet only one could be opened or interacted with. I went upstairs in a house and found a large pentagram on the floor, with candles at each point. Of course I tried to light the candles, cause that might make something happen, but they were merely painted background. Empty chests and candles that didn't trigger anything when lighted would have been fine, but the extreme lack of interactivity turned me off the game less than 5 minutes into the demo (though being a straight action RPG it would have needed something more than a 'kill monsters / upgrade equipment' cycle to hold my interest).
Back to the DD demo, I wanted the game before I got to the fourth level of the catacombs (or was it the third?), but after the existential skeletons I had to get it the day it came out. Humour and the various easter eggs added to the game.
VERY good points,i did enjoy these aspects of DD indeed!!it's a shame to forget them really.thanks raze
