A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate in the Unity community.
Separate names with a comma.
It may occurs time by time. Did you try reinstalling visual studio and unity?
Your game looks fantastic! You guy have done a great job. Can you share what kind of techniques you have used in those 3D? Say shaders?
If syntax is correct look at the project settings and see anything wrong in gravity
This thread is really useful I got to catch up those techniques