gaming hasnt "clicked" here yet, but Indiagames is one company that made it to
DEVELOP 100: THE WORLD'S MOST SUCCESSFUL GAME STUDIOS, their forte is web and mobile, even Rovio is not on that list, so they must be doing something right... still gave competition to the consoles as well...
there are many other fledgling gaming studios but mostly the focus is casual / web / mobile games
to do it on a professional level you need a professional certificate, this is available as part time courses as well, maybe you can pursue this along with your education. You can go via the mobile route and learn application programming or go via the design route and learn game design with 3D, game engines and game related scripting. Once either of these are done you can approach studios for internships.
there are intensive / full time courses available as well
you cant really sit at home and play games and earn money maybe you can look to "review" instead of "test"