I'm picturing a game where you take the role of an arcology planner and are given a certain number of ingame years to prove the viability of the concept as fully as possible. Game takes place on an isometric grid, where you build your arcology out of predefined modules such as living quarters, industries, power plants, greenhouses, etc. You have to manage things like the flow of resources between districts, transit, waste management. You can connect your arcology to the wider world to do things like import resources and export waste, and you will need to do so especially in the early game, but you also gain a growing ability to handle these things within your arcology as you expand its capabilities. Maybe also have the player have to deal with structural soundness and making sure the arcology doesn't collapse. Scoring would probably be based on population, land footprint (smaller is better), and self-sufficiency.
Hmm. Maybe after Guardian Cry.
One of the hurdles here is certainly going to be how are you actualy going to differentiate yourself as something other than another random colony sim or budget city builder.
Its not trivial, I actualy played the base Surviving Mars game but did not buy the DLC, you should look into the difficulties they had, but one of the biggest one on release was they had this complicated individual colonist simulation where each citizen had his own home and workplace and immidiately that raised the problem of transportation and it crashed heavily with the idea of individual mostly self-sustaining domes on Mars, something as trivial as allowing people to move between domes and suddenly you break a major premise i.e its not realy civilization's edge if you can have that much freedom.
Eventualy they fixed their game, they decided to compromise the original design for the sake of what the players wanted(i.e realy just a flavorful citybuilder not a deeply realistic take on colonization) overall I haven't come back but the consensus is its a good game.
But there was hilarious things like oh your colonists also age, so now we need to create dedicated retirement domes because otherwise it fucks the economy.
I mention all of this because an arcology means some very big restrictions on what agents inside the game will be able to do and as an extention a big restriction on how you want the players behave. This is quite a dangerous minefield, these genres say they're about having the freedom to build and do a lot of things so if you decide to have your cake and eat it aka "oh its another flavor of city builder but actualy you must play exactly how me the developer told you so then IDK about those prospects.
This really seems like a problem solved with difficulty settings rather than gutting the vision? If simulation is too difficult for fun gameplay then you spin that off into its own setting and limit features in lower difficulty settings intended to be more game-ey.
These are all good points. I have a few ideas.
Multiple different scoring criteria (e.g. population size, self sufficiency) that the player can prioritize - they can go for an overall good spread, or maximize any one, each of which should incentivize different city designs.
A "learn by doing" research system integrated into the city building itself. For example, recycling modules start out expensive and not really worth it, using a lot of power, processing very little waste, and recovering only a tiny fraction of resources. The more recycling modules you have operating, though, the faster improvements in handling waste are engineered.
Sunlight management. If all your residential and entertainment districts are in the center of the arcology, people will get sick of not seeing the sun and won't want to live there anymore. Sunlight would also be required for conventional farming (hydroponic modules would probably also be an option, but they would produce less food and require more power).
2d pixel art graphics. Not really a big hook by itself, but it would help it stand out visually.