The category you're looking for is Games Industry...

But generally, it doesn't seem to be so much getting into a college or getting grades, as much as having some game designing skill

"Game developer" is a pretty broad term. Do you want to be a coder? Learn to code. Do you want to be a graphical artist? Start drawing. Do you want to be a storywriter? Write some stories. You get the picture. The first thing you need to make clear with yourself is what exactly you want to do in that industry.