hi,
I think that an IP "Architect" should be about original, unexplored themes (not the ones who have been already exploited). If Prison Architect is so surprising for me, it's because i would never think that a game about a prison would be so funny and engaging.
Forget island (like Tropico), school (like academia school simulator).
Maybe:
* a big state administration (paperwork for paperwork): manage employees, budget, employee strike, syndicates, (unhappy) users, waiting line, office space, administrative procedures which lead users to successively go to such and such counters (procedure 1: counter A -> counter C; procedure 2: counter A -> counter B -> counter D)... It would be funny to play with the prejudices on the administration. The placements of the counters would be very important to optimise the flux of users and it should be the main stake of this game (architect!).
* an holy place in the antiquity: manage the flux of pilgrims/tourists, the training and accomodations of the priests, the objects of workship (order to the sculptors/artists, beauty, placement), the worship itself (sacrifice, length of the pray, religion for the elite or the mass...), manage the budget between donations; A lot of ideas to have and an humoristic angle. Architect so the drawing/extension of the holy place should be the main goal of the player.
* a cyberpunk pleasure place in a dystopia: nightclub, bar, whorehouse : manage the employees, the flux of clients, corrupt/blackmail the officials...
* a pirate station in space
* a laboratory in a strange planet: manage the researchers, the testers, the monstrosities (alien

) and of course, the construction of your scientific complex
etc...
i would buy any of these games without hesitation
