It was actually fairly quick and simple, considering they were looking to hire 200 people within the next month. After getting the call for an interview, I arrived and sat in a room with 6 or 7 others. In order to speed up the process, Carlos (the recruiter) interviewed us all in the same room, with each of us taking our turn to tell everyone our names, info about us, and answering a few questions about what sorts of video games we liked and other questions like that.
Afterwards, he took us all through a demonstration of what our job would be like. He brought up an old Alpha version of a racing game, and played through a few times, pointing out some of the bugs, and of course emphasized that we weren't playing the games, we were testing them for bugs and glitches.
After this, he told us he would take us each separately from the room to interview us separately, and asked one of us to step out with him.. After about 5 minutes, he stepped back in, and told us we were all hired. Him taking someone from the room separately was his way of playing a little joke on us. We were then taken on a tour of the facility, and then given the requisite run-down of company policies and signing of papers.