Sell the PS4 and buy a Wii U with Mario Maker.They will love it!
On a serious note,Rayman Legends seems a good bet, but if I were to give a game to him, I would give him The Nathan Drake Collection.Alot of content, enough to keep him entertained for quite some time, 99% a single player game, so no online issues there, and simply a fantastic collection, with simple yet addictive gameplay that anybody can enjoy.I dont think you can go wrong with this.
Edit:And as of now, it seems to be more than 50% discounted on amazon.com.So there is not excuse to not grab it!
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.
https://gamrconnect.vgchartz.com/thread.php?id=241866&page=1







