Hey there!
It's a good idea, i also got a few concerns. If it is open portals, that enemies could use them or that single Skeleton attacks a building close to the portal and murders peons on mass. A red Arrows would be nice to see which path the enemy takes in the next attackwave.
As an idea, make Red- and Blue-Portals, Blue only the Player can use, and Red only the enemy. And with Adventurers you could turn normal Red-Portals blue or reactivate Portals. A Archwizard or Wizard could also produce Portals, or be needed to hold Portals open.
Ideas:
Carters. A special Building which needs Grains and 1 or 2 Peon, which than drives Horsecarts around hauling items.
Trade: Trade with the Alliance via the Harbor (You can get lots of Gold, and have close to nothing to spend it on)
Weapons: Upgrades for Towers/Adventurers/Townguard.
Questions: Do you plan to add multiple difficulties? (May have read too much "I Became the Tyrant of a Defense Game" in the last few days)
Viewing post in Prototype is live — and I need your brutal honesty comments
I managed to get the Neferu's scene, was not repeatable tho. Neferu and the other would just "smile at me" when trying futher flirt attempts.
As for Relics, i cannot say for sure if they are working or not. (Says the guy who got the 25% Birthrate relic first and always had about 45% Children in the population)
I also got ideas for Relics, Relic-Buildings: Relic-Bakery, automated Bakery that just needs grain to function. An automated Arrowtower and so on.