In this Ma Thesis of mine I explore the philosophical notions of Johan Huizinga's Play Element and Jean-Paul Sartre's Intersubjectivity, in order to provide an overview of how video games work, through the career of video game designer Hideo Kojima. My aim is to show that these theories are applicable to video games in general, on the other hand it is more visible on famous designer Kojima's work. Through his art, I reveal features that might be found in most of the video games, in connection to personal experience of playing games and the connection between the virtual world and our, 'real' world.