Firstly, it’s not as exciting as you think.
During my career as a software engineer I have had the opportunity to count game testing among my primary functions. In the first instance I was working for a major semiconductor manufacturer who counted an audio chip among their portfolio. I got to do compatibility testing for drivers for folks that used the chip. The job consisted of running the top 100 games on various hardware configurations to make sure the sound worked right. Sound fun? Not so since all I really got to do was set up the systems run the game for literally a few seconds to make sure the sound worked properly so there was really very little actual game play involved.
The second opportunity was working for a gaming company that did slot machines. I wrote driver code for them so, of course, had to make sure that my code worked before it went to production. So, although I got to do a bit of testing, the real job was software development. The real testing was generally done by a bunch of co-ops (read students that work ridiculous hours for almost free so they can have something to put on their resume when they graduate).
So… your best bet is to go to school and be top of your class as in a software related field and get one of those co-op jobs, but be prepared to work hellish hours for darned near nothing. Then, if you are very lucky, you might be able to land a “real” job at a gaming company. However, be prepared to work even more hellish hours where the bulk of your time will be spent cranking out code rather than “blowing stuff up” (in the virtual world, of course).