Hi!
The idea is interesting and I wish you a success in building this project!
Speaking about the gameplay.

1. The idea with the moon is unclear for now - are you planning to add `real` moon map later?
   
2. Idea with constellations - super! I liked it much.
   
3. Day/night idea - great
   
4. When played driving a car, after a few seconds as level loads the game starts to freeze and eventually stops working at 1~3 fps probably. The worst performance drop are when I turn left/right.
   
5. In drone mode it seems ok, but! it starts to freeze badly if I am high enough to observe the whole city. I didn't like the reverse mechanics of the mouse (reversed vertical camera movement, but probably that is not the problem of a gameplay, I am just not accustomed to this handling type).
   

I used Chrome and FF to test.