Worlds Apart is a descendant of old-fashioned computer text adventures. It was designed using a very powerful interactive fiction language called TADS, which produces games quite similar in look and feel to the legendary Infocom adventures. As with those, you interact with Worlds Apart via a text parser, which accepts simple commands like "sit on the chair" and "ask the wizard about magic".
Yet Worlds Apart differs from traditional adventure games almost as much as it differs from a plain novel. It is first and foremost about self-discovery, not puzzle-solving, and is set in a richly detailed gameworld. This gameworld is filled with optional discoveries: while there is a central story which all players will experience, the majority of Worlds Apart is optional! The more you explore, the more you will find. This exploration includes both probing the world around you using your six senses, and speaking with the other characters.