Yes, it's a serious condition. Many people are addicted to increasing their virtual GamerScores and Trophy levels. Something inside their brains tells them that it is more satisfying to "complete" those small (sometimes time consuming or impossibly difficult) tasks than the actual game. They will force themselves to play poor titles just to round off those points, and they become immensely frustrated when they cannot complete them 100%.
It is not a video game addiction. A video game addiction would mean he could not stop himself from playing a game, and that it would interfere with his health, job, or social interactions.
What your friend does is ultimately up to him.