I felt a good place to start would be if I were to have the narrative nailed down. This then would let me go through the developmental stages with much more intention.
I started by figuring out the intro. How does this story begin? Within the intro I need to include some kind of mini tutorial. Because you are an employee of at the subject of your higher ups, to help establish a theme. I feel a fun approach could be for your boss to introduce you to the “game” and then give you a command that is out of line with goal 11. This then would prompt the player to challenge the boss and in turn learn the games mechanics before making any real progress.
From here I think the next step would be to create the meat of the game, that being the kind of interaction loop. I think it would look something like this.
This method would then be repeated until the city is a better place to live.
An interesting idea I had to replace the idea of the city score improving would be to have a character occasionally visit the player to inform them of their progress. I had the idea that this could be a pigeon. The pigeon would occasionally land on the windowsill by the players desk hinting at improvements that have been made off of the back of their influence. I wanted the pigeon to have a third dimension and a reasoning for visiting to office. This went a little rogue but I felt it was in line with that earthbound thinking. The pigeon would have a crush on the player and hint at how good they are doing whilst keeping that sense of absurdity that will compose the tone of the game.
This idea then led me to what I think could be a good ending for the game. That being upon rejecting enough bad ideas. Your boss, whom you challenged in the beginning would come back to tell you that he’s made some space and has a newer, nicer office for you. This one with a city view. The view of the city will show the player that they’ve created a beautiful city, one that is inclusive, safe, sustainable and resilient.