Today's tweens live in a techno-centric world that their parents never would've dreamed of at that age, back when video games were still in the primitive stage and the word "tween" didn't even exist. While the parents of today's tweens spent a lot of time playing outsidewhen they were growing up, today's children face a temptation to spend more time in front of an electronic screen of some sort than doing anything else. All of this screen time not only has the potential to expose your child to inappropriate images, it also takes up time that he or she could spend socializing, getting some exercise or studying.
To rein in your tween's screen time, talk to your child about why it's important to make room for other things in her life. If she wants to spend part of a weekend afternoon playing video games, encourage her to invite a friend or two over to make it a play date (but don't call it that!); this makes the game into a social activity, instead of an isolating one. Steer your child toward video games that involve physical activity, such as dancing. If your child shows interest in something such as computer art, introduce her to the physical version and encourage her to try different materials, like watercolors or charcoal, for example. There is joy and movement so encourage your tween to explore the world around her.
Your tween is growing up -- but with some reasonable limits, he can grow to be a much happier and well-balanced adult than he would have without your guidance.