Video games & autism

Alex's favorite pastime is video games. It's not a certain system or certain game. He will play anything and everything as long as it's a type of video game. Actually he likes board games too. I am not a parent that likes my child to spend a lot of time playing video games but it truly makes him happy. I will admit that he plays more than I really like him to because I am having a hard time finding ways to keep him entertained and happy at the same time. I would love it if somebody would give me some fun ideas for me and the kids to try this summer. I am keeping my 10 year old nephew, my son who's 8 (has autism) and my daughter who is 3. The boys are playing video games together and entertaining each other, which is an accomplishment for Alex to play with others. He prefers to play by himself most of the time. I am entertaining my daughter most of the time. Thanks for any ideas!