Oh i wonder how difficult it is to builds my own game...
Yes it is difficult.. But nowadays things are getting a bit easier because there are gaming platforms, like Unreal Engine, providing to us of ready pieces of code, objects and staff that we can buy or use for free in our game.
So, the following variables, function, code, may seems of a terrible headache, but if we study a bit of this field, it is sure we will like it. Oh let's make our worlds and scenarios...