To teach lifestyle changes more effectively than the written word can.

Genes don't determine outcome by themselves. Environmental factors play a role, a more significant role than most people seem to realize. Ants and bees know this and use this information to create queens from normal larvae -- ie ants and bees are adept at taking the same genes and getting a vastly different outcome. So it can be done.

(EDIT: There's a website listed in my profile which might give you some idea of what I do for my health. It doesn't convey enough though, so that's where a game would come in, assuming I can ever get there from here.)