Should I trade in my Xbox 360 to Gamestop?

I just got an Xbox 360 in Feburary. Everyone was on Kinect Sports online, now nobodys not. I havent touched my Xbox in about a week, and Im getting bored with it. Are there any good games with online out there? Also, I cant play M rated games, as Im only 13. if theres not any good games, should I just trade it in? BTW, I have a Wii and 3DS too.