From GI.biz: “The key components of all games — whether card games, board games, playground games or video games — are universal: goals, rules, strategy, challenge and interaction.
What’s even more interesting is that these components apply to all ages, which is one reason we have recently witnessed a glut of video games that were probably not designed with kids in mind but have, nonetheless, ended up becoming huge hits among that age group.”
Source: N4G PC Why kids aren't just playing kids' games anymore and what that means for developers