Question: Are the devs considering the possibility of buildings with two or more floors? I for one would love to see towers, small castles, town-houses.. a bit of medieval goodness.
Problem?: I guess that apart from the difficulty of the artwork, which is more a matter of effort than a technical matter, the main issue is the concealment of things. The larger the sprite, the greater the difficulties for the players. Now, thankfully we can actually see things by outline when they end up behind other things. However this is only really good for dropped objects. If we had, say, a short building built behind a taller building that conceals it, there would currently be no way of getting in the door of the small building, would there?
Solution: Outline the doors of buildings as well?
Alternative: What about scrapping the current system and opting for the translucent aura around the player character? That is, if you go behind something, a small radius is rendered visible.