There's a ton of kid-friendly stuff for Nintendo systems. L. loves fantasy, so I recommended the Dragon Quest games. Cary beat me to Okamiden as a recommendation, and with a DS Lite, he can still play GBA games, so I might recommend a bunch of those, too.
Oh, Bandit! I was trying not to laugh as he kept evading me and doing that doggie play-bow thing and heading back to the front of my landlady's house. My feet were frozen, though. Mud boots are not meant to keep one's feet warm!