https://www.youtube.com/watch?v=J9tjP5JuP9Q

so i have been watching let's play and wondering, "how do they make those environment, characters, animations, music"

especially environment and characters...since, objects.
all i know is bars and cables, bars and cables.

How much of modules are considered enough for a set of time/duration of a gameplay?

edit: this has somehow expanded so far into other things.