Well, first off you'll need to take up either Flash or programming.
if flash, you'll just need to study a lot of functions and programming languages. As well as get very good at drawing /illistrating on PC.
If c++, you'll need to not only find and use a game engine and physics engine, but study a lot of 3d modeling and CAD work, become an expert texture painter, learn how to incorporate your models into the game engine, as well as produce a storyboard and blah blah blah blah blah
go to school for it.