You can try supplementing the video "games" with other interesting activities. It is best that you also help him find other outlets and introduce him to other educational software that is challenging and fun.
Try and draw his interests towards other activities. ( I suggest an outdoor sport or something of the sort) Really though, kids will always be interested in video games. The industry usually targets kids at that age. Kids find them more appealing than most adults. ( except for me, I LOVE video games) Anyway, try to monitor and limit his gaming. :)
The question you will write in the future is how can I get my 20 year old off the couch into a job and out of my house. Just letting you know they are very addictive and your kids health and education are at risk if you don't just break it.
In my opinion he's a child and he should be allowed to play games if want to, but as long as it's not too long. And if that's the case then maybe set a certain amount of time for him to play games and then cut him off and get him to go outside and play or family activities or watch television or movies with family....
Get him into role paying video games. Even better, take him paint balling or to laser tag. Or go cart racing. Get him a skateboard and take him to a skatepark. Play with him. A trampoline is also something hell probably love. Remote controlled vehicles, nerf guns. My little bro is 10 and he'll play mine craft at any opportunity possible. From approximately ages 8-12 he'll want to play video games a lot. The best thing is to take his favorite character from a movie, video game, or tv show, and find fun activities, that you can get him to do by telling him they will make him more like that favorite character of his. That always works the best. Be a friend, not a tyrant. It'll also help with a better relationship not only now, but as he gets older.:)
Kicking the habits of video games is too hard to leave. Being a parent, we need to set strict limits and monitor usage of computers. Therefore, keep the computer or game systems out of their room or wherever there are live. Utilize their time for homework and communication with friends.