Minecraft is easy, I think. Bear in mind that I only know because I see two ten year olds play it all the time.
Your son may tell you that I don't know what I'm talking about, but here goes. Start a game of Minecraft on one iPad, then join it on the other. Dump all of the stuff into chests, or whatever they're called, then "Quit and copy map" on the mini. All of his diamond armor and blue sheep and whatever else should be saved on the mini.
I hate Minecraft. I never thought I'd be able to answer a question about it. Now I'm scared that I might be right. God. I'll be playing HayDay next!!!
Sent from my stock iPad 2