Now that the MCP3D Microeconomy has been finally released on the Ethereum mainnet (https://play.mcp3d.com) it may already be the most complicated blockchain entertainment project released so far.
A lot of strategies possible in the MCP3D, just to name a few:
Almost any building in the MegaCryptoPolis 3D is able to produce non-fungible tokens those are required by other buildings to operate. Being it a Citizen, Resource (like Electricity and Water), Material (Bricks, Wood, Stone, etc.) or Appliances there is someone who needs that.
One could possible build a full production chain the MegaCryptoPolis 3D with all types of buildings to satisfy every need for further development, but that would be a whole lot of a story. Purchasing required components on the market is way more effective way of making business in the decentralized city.