Then there's Hippo, the protagonist. Hippo is a pygmy hippo. Very small. About the size of one of Supersize's feet. Hippo is the one who has to keep Supersize fat, happy and uneaten. Being so much smaller than Supersize makes the task very difficult for him, so he relies on various tools like lassos and remote controlled robots.
I'll freely admit I have no real idea what would keep a child interested in a game. I have noticed that one thing that gets to the parents is the sometimes monomaniacal obsessiveness their children show towards one thing. Now, I can't promise that the kids will find my game that fascinating, but what I can do is provide facilities so the parents won't be driven insane by hearing the same thing over and over again.
So what can I do to solve this? First off, having a cast of characters. Game play will focus on Supersize and Hippo, but everynow and then another character will show up and interact. Or just say hi.
Another way is to have multiple takes for various voice clips. Rather than only record Supersize saying "Eat Me!" just once and reusing it, the game should have multiple takes floating around. Or the moos.
It would probably be good for the game to allow parents to download and install new "event packs". For example, new ways Supersize tries to get eaten. Then again, it might be better to allow for automated installation. After all, if a parent lets his or her child play a game about a suicidal cow, they probably wouldn't worry too much about the content of potential add ons.
Finally, I'd like some way to balance out the occurance of special events. Like when a new special event is downloaded, it tends to pop up more frequently, then evens out as it occurs.