If your media makes a big deal out of him gaming, read better media. If you can't find any, stop reading. You're probably better off.
His manifesto actually (readily available in english) makes a big deal out of how pretending to have a gaming addiction is really usefull for hiding nefarious activities. He wasn't a gaming addict, he was using it as a cover.
Also, if your media is one of those who kept harping on about this being muslims long after it was clear he was Norwegian you're probably better off without them either (I'm looking at you NY Times). The american coverage of this incident has been pretty much abysmal, and I'm sorry for being able to read english. I wish I couldn't.
However, while his gaming certainly didn't affect him, it's pretty clear that the fact that he was taking a coctail of anabolic steroids did. He even described it himself in his manifesto. To which extent we won't know until later, but we'll figure it out. There's plenty of time, and we have to grieve a bit of first.
Signed
A Norwegian
(Also; Glenn Beck; May you burn in hell)