I realize that to a certain extent the answer to a lot of these might be “sure, once someone mods it in”, but at least potentially, will this game have or let me . . . .
. . . build houses up in the trees?
. . . flowing water? Rivers? Waterfalls?
. . . magic?
. . . nonhuman playable races?
. . . subterranean spaces (caves?)
. . .destructible buildings or terrain (i.e., can a Titan stomp on my house?)
. . . machinery? Windmills, etc? Drawbridges?
. . . seige engines?
Those were all I could think of right off, but I’m sure other people can think of other types of things they’d like to know whether or not they’ll be in here (and/or things people might be interested in modding in).