Various new forms of entertainment using information and media technologies have emerged and been accepted among people all over the world. Casual and serious games, as well as communication using mobile phones, blogs, and Twitter, are such kinds of new entertainment. It is important to discuss the basic characteristics of such entertainment and to understand the direction to which these new forms are leading human societies. This paper provides a comparative study of entertainment between developing countries and developed countries, and between ancient times and the present day. The future relationship between entertainment and society is also described.