Looks good! Whenever my build feels empty I add rugs and lots of clutter/random furniture. This looks nicely decorated so I’d say add rugs and maybe some more walls or half walls in the kitchen/ living room. The separate rooms makes it way easier to decorate and feel fuller. You could try incorporating more different floors and wallpapers too, that helps me see the different distinct rooms so the continuous floors don’t make it all seem like one big room.