|about two years older than this. But still, tiny hands!
1. Have custom avatars: Kids want to pretend they are in the game, and they want to have an avatar that looks cool, preferably that they can change at will. Pepper's favorite part of Little Big Planet is selecting the "random costume" button and saving them, and decorating his pod. He was reluctant to play Kirby's Epic Yarn because Kirby is pink ("I want to be a guy" "He is a guy").
2. There doesn't have to be a big bad boss, it's good enough to just have a fantasy world to explore. Pepper's favorite LBP levels involve driving, roller-coaster riding, and pretending to swim with the sharks. The cantina in Lego Star Wars, where you can just run around attacking anyone at random, is also a favorite. I'm bored by roller coaster levels ("I'm just pressing down R1 this whole time..."), but he thinks they are fun. I think other kids are similarly motivated by fantasy in the video games they play.
3. Make it really easy. Kids this age can learn to do things more complicated than jumping, but they don't have a very high frustration tolerance. Many of the puzzles in Lego Star Wars are too hard for him to figure out without my help. Not just puzzles, but basic controls should be simple. I feel like the wii is a little nicer for this, but when you add in the nunchuck there are still lots of buttons, which might explain the popularity of ipad games with this group. Having the buttons doesn't mean you need to use them; point-and-click PC games are also really fun.
4. Potty jokes are hilarious, but it should also be exciting (but not actually dangerous)! Things like playing house, pretending to cook, eat, and sleep, come naturally to pretend play without a video game, so it feels natural in a game setting. That said, there should be something attention-catching about a game for this age group--something they already like, like monster trucks, dinosaurs, trains, roller coasters, Mario, sharks, jungles, etc. They want the feeling that the game is dangerous, but they don't want to die in the game (so, some kind of fire-y background is great).
It's easy for adult gamers to keep insisting that video games should be taken seriously and want more serious games, but I think it's also important to remember kids in video games. THEY LOVE THEM.