I think buildings in the Demigod beta are lacking in design.
1. The looks: the scale is out of the window
The idea of a growing Stronghold is good, but it only grows vertically. And above all, it's small to begin with. It's not impressive. It should start much bigger and grow much bigger.
All the buildings are way too smal IMO. Assaulting a castle or a tower with Minotaurs is like assaulting a (big) sand castle. The tiniest creature is half the size of a tower. The smallest demigod is larger than a powerful tower?!?
To me, buildings should simply be twice as big. Why? Because epic battles and assaults should take place in impressive environments. The Rook could be made slightly bigger also. You don't want kickass Demigods to fight against buildings that look like toys.
Building with appropriate scale = Epicness = awe inspiring factor.
2. The looks: item shops
They are ugly. They should be bigger, have real and different textures, and signs / symbols to reflect what you can buy in them.
Seriously, they look like temples for dolls, are the size of chests rather than actual temples. It's lackluster.
3. The strategy: new buildings could be bought to help with defending certain zones, produce additional special units, etc. Your camp could look like a real base of operation, with strategic targets that appear in the course of the game, to spice things up.