If you move forward for commercial game, I think you can have solo, PvP or team vs team. You work as security guy in the mall and someone gets to the information counter saying they lost someone and give you the photo and the last position where they got lost. You should navigate as a person rather than flying. You can add some mechanics like if you ask someone if they saw the person in the photo and they may tell you yes (where) or no, but it consumes time. You can maybe check for some security cameras (you need to play a lot to know where they are) to see whether you can see where the person moved forward.
If I would be in your shoes, polish it a bit, release it and test it with as many people as you can find. If they find a hook and there is replayability, test some mechanics and repeat. The path will be clear.
Once the mall is completed you can add other scenarios (a village?, a mall?, an office?) and game is served.
Maybe you can get inspired by "Spy Party" game.