I hope this topic wasn't already made, haven't found it yet and maybe my suggestion is pointless if It is so I am dearly sorry.
Well what kills the game atmosphere now is the background, which looks like we where in the highlands. I heard it all takes place on an small island so this obviously might change drastically. I hope this is only in the demo back from a very early stage but I kinda find it awkward seeing all this grass land while it would be easy by using some scripts to create a lush Forrest. Render it one time and than use it as a picture. Hell I could do it (okay I am already advanced at 3D so what a surprise), so I kinda wish there would be something nicer in the beta already. And I just want to suggest to keep an eye out for this part because it can truly destroy the atmosphere. Also for now the water looks like mad. I mean the waves are great, they actually look pretty good no clear repetition and definable wave patterns. But it still needs more to it. And that ugly water could easily translate to the finish game and that wouldn't be that good.
I know this might sound a bit silly seeing that it is still in beta. But it is ruining what is otherwise a visual perfect and truly marvelous game.
Well that are my suggestions/thoughts on the background.