Are there video game developers in Pittsburgh?
Yes! GameDevMap lists them here: http://www.gamedevmap.com/index.php?tool=location&query=Pittsburgh including Schell Games, Sim Ops Studios, and ImpactGames
Video game developers can come from many different backgrounds. When taking the academic route, developers typically major in computer science or a related field in order to gain knowledge and credentials that make them attractive to companies. Other developers are self taught and take standardized tests that will be able to give them credentials. Internships are always a good way to get a start in a developing company.
Developers actually program the game and make the models, textures, etc. They are like the construction workers on a building. Publishers market the game and finance the development. They also arrange the manufacture of the disc, the package, etc. They are like the business men who are financing the project.