PilzFTW :
Haha, he does go outside around 2-3 hours a day and reads 30 min every night.
Okay, well to actually think really hard about that question "Are there any great alternatives?"
Grand Theft Auto Alternative: Saints Row? That game is more offensive and less realistic. So no.
Far Cry 4: Crysis series? A FPS based in tropical environments. It's similar enough and critically acclaimed.
Dragon Age Inquisition?: Well, it's got sexual content, all games similar to it are made by the same developer and also tend to have that content as well. I can't think of an alt for this one.
Watch Dogs: It's GTA with hacking. Can't think of an alt.
Assassins Creed alt: I literally can't think of a similar game like Assassins Creed....
I'm sorry for failing you.
No BS though, has your kid played Plants Vs Zombies: Garden Warfare? An online 3rd person shooter game that's very fun, addictive, not to mention family friendly.